The Professor did not say anything  in reply. Muttering something under
his breath  he quickly set out  in the direction  of  the  cave.  Valya  ran
skipping along behind him.
     "Now, Professor dear, do tell me  what are these horses? Where will you
get them from?"
     "I will not tell you!"
     "Tell me!" insisted Valya.
     "Don't be curious! You'll see for yourself to-morrow."
     "Oh, Professor," whimpered Valya again, and suddenly became silent.
     In front of them a light twinkled. Valya seized the old man by the hand
and stopped.
     "It's on fire! Look! There is a fire in our cave!"
     The light was coming between the rocks  which  blocked  the entrance to
the cave.
     "A fire! A fire in our cave!"  Valya screamed in fright. "Hurry - Karik
is burning!"
     "It is nothing! Nothing terrible! Your brother is not burning."
     But Valya,  not listening to the Professor, had already dashed headlong
to the cave.
     "Karik!"  she shouted, as she ran.  "Are you burning? Are  you burning,
Karik?"
     "No, it is not I," Valya heard Karik's calm voice.
     She quickly  pulled the rocks aside. Jumping into the  cave she stopped
as if she was rooted to the spot.
     "Whatever is it?"
     The  corner  where the mound of little eggs had been laid on their tray
was glowing  with a dazzling  blue light just as the lamps  on a  New Year's
tree, only brighter. One could have read a book by the light.
     "Well, how do you like it?" Valya heard the old man's voice behind her.
     "Isn't it lovely !" said Valya, in ecstasy.
     "It's those . . . those eggs are glowing."
     "Yes," smiled the Professor, "the eggs of a glow-worm."
     "Ah, I know!" Valya  nodded  her  head. "It's that worm. The glow-worm!
The 'St. John's day' worm, as the peasants call it!"
     "Yes,  that's what it is called, although it actually is not a worm but
a beetle. That you can easily understand when you consider what it eats. The
ordinary worm lives underground and eats earth but  the beetle lives in damp
grass and feeds on snails."
     "Yes, yes! I remember. These beetles shine in the grass."
     "Perfectly correct. They glow  themselves,  their larvae glow and their
eggs glow. . . . Pretty, isn't it?"
     "Very pretty,"  said Karik from his corner. "How lucky  it was that you
found them."
     "Well, now how do you  feel. Better or worse?" The old man went over to
the patient. "Would you like something to eat?"
     "Had it !" said Karik. "I have already had it! When you were away I had
a look all round, found the honey and had a jolly good feed."
     "You shouldn't have got up." frowned the Professor. "It is too soon for
you to  get  up ! Too soon,  my dear!  If  you don't  look out  you'll  make
yourself worse !"
     "Do you know what?" said Karik. "When I woke up and looked around - the
table, then the  chairs, and the light burning. Why, I thought I was at home
again, it was morning, and I must get up."
     "But do you like our new flat?" asked Valya.
     "Very much!"  replied Karik. "Particularly the little glow-worm  lamps.
Haven't they got a strong light?"
     "You  could  have  more  than that,"  said the  Professor.  "Now if you
brought a couple of Pyropheri in here . . . there you would see some light!"
     "And what are these things . . . py . . . your pyrough."
     "They are beetles,  too! They  live  in Guiana, Brazil  and Mexico. And
then if  some Brazilian or Mexican wants to go out in the forest at night he
catches one of these beetles and fastens it to his hat. The  light given off
by  these  beetle-lanterns  is so strong  that you  can  go through the very
darkest  of  tropical  undergrowth and not lose  your way - some people call
them 'Ford bugs' because  they are  like  motor-car headlamps. Mexican women
adorn themselves with these  Pyropheri They hide  them in their hair, beside
diamonds or make themselves jewels of fire or fasten them round their waists
to  make a girdle  of fire. After a ball the  local  belles bathe the  tired
insects in a bath and put them in a glass vase and there the Pyropheri light
the  bedrooms  of  these  Mexican women all night  with a  gentle,  pleasant
light."
     "But is the glow-worm the only one we have which glows?"
     "It's  not the only thing," replied the Professor. "I could arrange the
same sort  of lighting using  glowing bacteria. . . . When I was a student I
once  made a real lamp out  of such  bacteria. By the light of this  lamp  I
could read and write."
     "Bacteria? These are so  small that  you cannot see them with the naked
eye. How can they light up anything? You couldn't see them."
     "When you  have  lots of them," replied the old man, "then you can  see
the light,  although  the individual bacteria,  naturally,  cannot be  seen.
Often in  the  forest you can see Rotton stumps glowing with a blue or green
light. It looks as if the stump  itself was glowing,  but  it  is really the
light of the bacteria. In the same way Rotton  fish thrown away on the shore
glow. Often you can see the same light in the carcases of animals."
     Here the Professor hesitated, ran over to a barrel and throwing the lid
off it noisily shouted cheerfully:
     "Supper, supper, my dears! Supper and then bed!"
     In  the  morning the  Professor  set out on a scouting  expedition.  He
returned only at nightfall and brought a coil of spider's  web cord. He then
sat at the entrance of the cave late into the night twisting thick ropes out
of the spider's cord. When they were all about to go to  sleep he announced,
turning to Valya:
     "To-morrow you  and I  will go to  our ship! It's time to launch her in
the water. . .  . Karik is getting better and we should very soon be able to
continue our journey."
     Next day the old man woke Valya before dawn. They breakfasted on honey.
     Then  he slung  the  rope over his shoulder  and set out  with Valya to
start work.
     The oak leaf lay in the old place.
     The Professor threw the rope down near the leaf.
     "But now," said he, "let's go to the stable for our cart horse."
     Then he led along the  bank, bending down to the ground,  looking under
the rocks.
     Beside a big  grey  rock he went  down on  all fours, looked for a long
time into a dark hole under it and then sat back and threw a handful of sand
into the hole.
     Something stirred beneath the rock.
     "A famous  steed!" announced  the Professor, getting up.  "If  only  he
doesn't kick we'll soon launch our ship."
     "What is there? Is it under the rock?" asked Valya, in a whisper.
     "A wild horse!" joked the Professor. "A  horse  with six legs. Now come
on, little Valya, you must help me!"
     He dragged the spider's web rope  to the stalk of  the leaf,  wound  it
around the stalk and  with an effort dragging the rope  over his shoulder he
pulled the knot tight.
     "Excellent!" he muttered.
     Dragging  the other end of the  rope over the ground  he walked with it
away from the leaf. When the rope was stretched full length  he tied another
loop in the other  end  of it. Then he dragged four short logs  of  wood and
stood them on end like ninepins stand when you are playing skittles.
     Lightly hammering the logs with a stone the old man drove them a little
way into the earth. He knocked one of them with his foot.
     The log fell down.
     "Fine!" announced the Professor.
     He picked up the fallen log and stuck it in its former position.
     Valya was watching  him with curiosity but could not make head or tails
of what he was doing.
     "Can I help you?" she asked at length.
     "Not at all, not at all! I can manage!"
     He lifted the loop of the rope,  dragged it to  the logs  and carefully
laid it on top of them.
     The loop  now  hung above the ground resting on the  carefully balanced
logs.
     "Well, there's the horse's  collar ready," said the old man. "Now let's
go and find the horse! Have you ever harnessed horses?" he asked, jokingly.
     "No," Valya acknowledged frankly. "I have never harnessed a horse!"
     "Marvellous! Nor have I. However, that's no great misfortune."
     The Professor picked up a long stick from the ground and held it out to
Valya.
     "Come! Take hold of this!"
     Then he found an even longer  stick for himself and putting it over his
shoulder, commanded:
     "Follow me !"
     With long strides he led Valya to the big grey rock.
     Near to  the  rock he stopped,  drove the  end  of  his  stick into the
ground, and putting one foot forward, said:
     "Now listen attentively. Just here under the rock there is the Carrabus
larva  hiding itself from the light of day.  Now  the  Carrabus is a vicious
beetle  which lives  on insects. This larva, like its parents, also lives on
insects. By day it sits quietly  under a rock, but at night time it goes  on
the hunt. It is extraordinarily strong! A regular tigress - nothing less!"
     "I  am frightened," whispered Valya, looking at the Professor with eyes
wide with fear.
     "Quite unnecessary!"  replied the old man.  "Just listen. Now then,  we
must  drive the  Carrabus larva from under  the rock  and  chase it into our
horse collar. Once it is there it will pull our ship to the lake. I think we
can manage the insect quite easily, only we must not be frightened."
     "But will it suddenly bite?"
     "Of course it will bite, if we get careless!"
     "Then how are we going to drive it?"
     "Just this  way: to begin with we'll chase  it out from under the  rock
and  then you  will stay  on that  side of  it and  I on this. As soon as it
starts  to  come  out  you  prevent it  from  crawling to the right whilst I
prevent it crawling to the left. We can drive it straight into the loop. Now
are you ready? Get a bit further away."
     Valya ran a little way  away. The Professor  shoved his stick under the
rock and started to twist it about like a poker in the fire.
     "Aha! it's coming! it's coming!"
     A huge monster with  a  long body  started to crawl out  from under the
stone  straight towards Valya. She hit it  with her stick  on its back.  The
Carrabus quivered and turned towards the Professor. He tapped it on the head
with his stick.
     Then the monster, moving on all six legs,  crawled straight towards the
oak leaf but on the way there suddenly stopped.
     The old man  ran up to the insect and gave it such a whack on its  back
that it shuddered and started to turn around where it was.
     "Valya, drive it, drive it!"
     Valya struck the Carrabus a stroke on its side.
     "Now, now! Get on! Get on!"
     Thus, step by step, they moved towards the oak leaf, driving the  larva
ahead of them.
     At last the  monster's head was level with the  loop. The Professor hit
the logs with his  stick.  The loop fell over the head  of the Carrabus. The
old man threw his stick down, seized the rope with his hands and pulled with
all his strength. The loop tightened. Then  he picked his stick up again and
ran up to the head of the insect.
     "We're off!" the old man shouted.
     The leaf  tumbled. Raising a cloud of dust it then slowly moved towards
the bank.
     The Carrabus turned from side to side, but each time bumped  up against
a sharp stick. The travellers would not allow it to turn  away either to the
right or to the left.
     At last it became more peaceful and dragged the heavy leaf to the lake.
     It crawled along, glancing  at the Professor  and Valya with  huge eyes
quite  unable  to follow what these  terrible  two-legged insects armed with
long sticks wanted.
     "The chestnut grey horse! A champion," shouted Valya, with delight.
     "Not  a  chestnut  grey  horse  but  a  Carrabus Cancellatus," said the
Professor, sternly. "Carrabus is  a genus of beetle of the  family Carabide;
Cancellatus is its name!"
     The Carrabus larva dragged the oak leaf to  the  water's edge, but here
it became  quite  crazy.  It made  a  dash  suddenly  along the edge in  one
direction and then abruptly turned around and dashed off towards the bank.
     The Professor  and Valya ran, shouting, after  it and hit it with their
sticks on the head, sides and back.
     How long this  struggle  would  have continued it is  difficult to say.
However,  it  finished quite unexpectedly: running  past  a huge  cliff, the
Carrabus stopped and then disappeared under the cliff.
     "Phew!" puffed the old man. "Well, that's  the Carrabus! 1 am afraid it
didn't like us."
     "But how are we to unharness the Carrabus?"
     "Very simple!"  replied the  Professor, untying the rope from the stalk
of the  leaf. "Although it's a pity to throw away such a fine rope, there is
nothing else to do! Come on. We have done enough to-day, don't you think? We
must go and have a bit of a rest."
     Leaving  the  leaf  on  the shore, the travellers returned home.  After
dinner Valya recounted to Karik how skilfully  they had dragged the oak leaf
to the shore with the help of the Carrabus larva. Karik listened to her with
envy,
     "Eh! What a pity I wasn't there," he sighed. "I would have got it to go
straight into the water. You should have tugged at the loop."
     "It  is easy  to advise,"  said the old  man, "but you should have been
working on the job as Valya and I were."
     He put his hand to his  whiskers, wiped the honey off his beard and got
up.
     "To-morrow we  must set out quickly on the expedition. But to-day until
evening  comes we  must  drag  the barrels of  honey on  to the  shore, find
clothes for ourselves, get  the mast, sails and ropes ready. In other words,
there's plenty to do."
     He took an armful of silkworm hair from the ground.
     "Come on, little Valya!" he said, turning to the mouth of the cave.
     All day long the Professor and Valya worked  on  the shore of the lake.
Valya platted cords out of the hair, and the old man wandered about  looking
for a mast.
     At last he returned. On his shoulders there lay a long, dry grass mast.
     That evening the leaf was launched in the water.
     The  Professor hammered a hole  in the  centre of the leaf with a sharp
stone, drove the mast into the hole and afterwards smeared a thick  layer of
clay on the floor around the mast and announced:
     "To-morrow the sun will dry  up the clay  and our mast will be fixed to
the ship as firm as you like."
     The  Professor gazed  at the ship,  thought for a bit  then took a long
cord from Valya's hands and went up to the end of the  leaf. Here he threw a
loop over the stalk and pulled it with all his strength.
     The leaf  quivered, its end  lashed  in  the water  and  then lifted  a
little.
     Then the oak leaf became quite like a ship.
     It rocked with its nose high above the water.
     "It's like a goose sticking its neck up."
     Valya started laughing. "Now if only there was a sail to put up!"
     "There will  be a sail too," retorted the Professor. "We'll make it out
of some sort of petal! Only it is surely not  worth  putting it up now! It's
already too late in the day. And what's more it would dry out in the sun and
become like leather."
     The old man drove a  sharp  stake into the ground and fastened the hair
rope to it.
     "There we are, everything is fine!"
     Valya went along  the rope  to the bow of the ship and with a piece  of
shell started to draw something on it.
     "What are you up to?" demanded the Professor.
     "I want to give our ship a name!" said Valya.
     "What have you decided to call it?"
     "Take a look at it!"
     Valya jumped down. The Professor went up closer and wrinkling his  eyes
made out in big letters on the bow: CARRABUS.
     "Not bad!" he said, approvingly.

     * * * * * *


     Next  day the  travellers  sewed clothes  from petals, and then in  the
evening Valya and the Professor rolled the barrels of honey on to the ship.
     Karik was  already up.  He walked about holding  on to  the side of the
cave with his hands and  wanted  all the time to  try and help the Professor
and Valya, but the old man stopped him.
     "Lie  down, take it easy,"  the Professor grunted at  him.  "You should
rest for another two or three days. We can manage without you."
     This annoyed  Karik greatly, but he didn't start to dispute  it. He lay
down on his bed, turned his face to the wall and made it appear  that he was
asleep, although he himself was stealthily watching the other two.
     "All right," he thought. "You'll go off and I'll do  half the work here
without you. Afterwards you'll jolly well have to thank me."
     As soon  as ever the Professor and Valya had gone out  of the cave  lie
jumped  up, seized  one  of  the barrels and started  to push it towards the
mouth.
     He  had already rolled it out of the cave when an accident  happened. A
round stone turned over under his foot.  Karik  flung up  his  arms and fell
forward with his  body on the barrel. The barrel  tilted over as a result of
this violent impact. He quickly clutched the edge of  the barrel, but losing
his balance fell to the ground.
     The barrel  rumbled  down  beside  him. The lid  flew  off'. The  thick
gruel-like honey spread out over the ground.
     Karik got up. Shaking the dust off himself he gazed  perplexedly at the
overthrown barrel.
     "That's a fine way to help!"
     The honey puddle crept in all directions like liquid dough. Karik moved
out of  the  way, looked  around  and, finally waving his  hands hopelessly,
hopped back on one leg into the cave.

     * * * * * *


     It was already dark by the time the Professor and Valya returned. Karik
heard their voices in the distance.  He quickly buried his  head in the hair
pillow and pretended to be asleep.
     "Oy, whatever is this?" shouted  Valya, stopping at the entrance to the
cave.
     Karik stuck his fingers in his ears and screwed his eyes tight shut.
     "Oh, I can't move!" shouted Valya. "My feet are stuck in the ground."
     The old  man dashed  to her  aid, but he had no sooner reached her than
his own feet got stuck in the sticky honey.
     "What can it be?" he wondered.
     Sinking  in  up to the ankles he managed to reach Valya with difficulty
and stretched out his hand to her.
     "Give me your hand!"
     Valya  gave a hand. He  stepped  back  and pulled her  towards himself.
Valya swayed and almost fell: her feet were fast stuck in the thick honey.
     "Stop," she yelled, "I am quite stuck! Like a fly in the jam."
     "Don't worry, don't worry," muttered the Professor, and took a breath.
     He dragged Valya out of  the honey with a great effort, took her in his
arms and  moving  his  feet with  difficulty started to  stagger towards the
cave.
     Under his feet the honey sucked, champed and sighed as if it was alive.
The mess clung to the feet like very heavy sticky clay.
     At last the old man got clear of the puddle. Setting  Valya down on the
ground in front of the  entrance to the  cave, he started to take the  honey
off his feet with a thick stick and then he helped Valya to clear herself.
     "Eh,  Karik!"  shouted  the  Professor, looking  into  the  cave. "What
happened here?"
     Karik buried himself still deeper in his mattress.
     The old man and Valya looked at each other silently.
     "Well, it's clear," said the Professor, going into the cave, "that this
is certainly  something that  Karik contrived! And what's  more  he  is  not
asleep! He is listening  to everything! But he is ashamed to look us in  the
face. Eh, Karik!"
     Karik cautiously turned his head and opened one eye. Then he saw, right
by his  side, Valya was looking  at him. He hastily screwed up  his  eye and
snored very loudly.
     "He's asleep!" Valya started to laugh.
     The Professor put his head from side to side but said nothing.
     The travellers went to bed.
     A  little while after dawn Karik heard, through his sleep, some sort of
noise. He  got  up  from  his  crumpled mattress and  went  to the entrance.
Through the chinks between the rocks he saw the terrace in front of the cave
in the pale light of the morning.
     On this terrace huge winged monsters were  crawling about just in front
of the cave.
     Karik  recognised them. They were flies. Bustling around the puddle  of
honey  they  jostled  each other, flew upwards with  buzzing noises and then
swooped down  to  the honey once  more.  Every  minute  more  and more flies
arrived.
     The  loud noise awakened  the  Professor and  Valya. The old  man  said
something,  but  the children  could not hear  a single word. The flies were
buzzing so loudly that their ears rang just as if powerful aeroplane engines
were running right beside them.
     It was quite impossible to drag the remaining barrels  of honey over to
the ship. The flies might knock the  travellers off their legs and even kill
them. They were crowding at the entrance, had started to peer  into the cave
and were thrusting their long snouts through  the chinks between the  rocks.
They  crawled over the rocks which were blocking the entrance  and under the
weight of the flies the rocks started to shake.
     The  travellers gazed  in fear at their barricade. It had only  to fall
down  and the hordes of flies would burst in - then they would  be - goners.
However, towards evening the flies crawled away to their night quarters.
     "They've  gone away  !" Valya  announced joyfully.  "They  haven't gone
away," said  Karik,  listlessly. "To-morrow  they'll be back  and  once more
they'll try  and get into the cave. I  know them! They can scent the barrels
of honey!"
     "Let's block up the entrance better!" proposed Valya.
     "Nonsense!"  said the Professor. "Sit another  whole  day trembling - I
should thank you!"
     "But what can we do?"
     "Attack!" announced the old man, "attack and not defend."
     He seized one of the diatom baskets, took a firefly  egg  from the tray
and holding it high above his head as a torch, ran out of the cave.
     "Where are you off to, Professor?" the children shouted.
     "I'll  be  back  directly.  In  a minute I'll give  them a  treat,  the
blackguards!"
     The blue light twinkled in the darkness and disappeared.
     "Where is he off to?"
     "I don't know! He must have thought up something."
     Late that night  the Professor  returned to the cave very contented and
cheerful.  He put the basket down  on the floor and, panting a little still,
said:  "There!  I've brought  the mines! To-morrow  the flies  will  find  a
minefield."
     The children rushed to the basket.
     "Mines?"
     "That's better!"
     Karik put his hand into the basket cautiously and drew out a grey lump.
     His face fell.
     "Some mines! Nothing but Rotton old clods. Simply dried  mud. These can
hardly be mines?"
     The Professor started to laugh.
     "You  don't  like  them?"  he  asked. "Don't worry!  You  just see what
they'll do to-morrow. A charge of gun cotton wouldn't do better."
     He  extracted the  lumps from the basket,  divided them into two heaps.
Having pushed the smaller lumps to Valya, he said:
     "Pick them up, Valya, and come with me!"
     Ladened with mines, the Professor and Valya went out of the cave.
     "Lay  your mines aft  around  the  entrance!" Karik heard the Professor
saying.


        CHAPTER XVI

     The battle with the flies - Extraordinary sails - It sees with its feet
- A bug plays the fiddle - On board the bumble bee


        "CLOP! CLOP!"
     The  children jumped  out  of  their crumpled, scattered  beds. Rubbing
their eyes they looked around in alarm.
     "Karik, what was that?" .
     "I don't know."
     "May be someone in our minefield?"
     The usual blue  light  glimmered  in  the cave.  The dark roof hung low
above the head. In the corner along the  wall white stout  barrels  stood in
rows.
     "Clop! Clop! CLOP!" Explosions sounded beyond the wall.
     The Professor got up from his  hair mattress, yawned widely and rubbing
his sleepy eyes with his fists said:
     "Aha!.. . they are working. .. . My mines are working. . . ."
     The old man  with the  children  following him went up to the barricade
blocking the entrance to the cave.
     Through the chinks between  the rocks the morning light was peeping in.
The  yellow  sand of the  terrace  in  front of  the  cave was  ablaze  with
sunlight. The  puddles  of upset honey  shone like  liquid gold.  The  white
barrel still lay there on its side.
     The travellers had to screw up their eyes, the light was so intense.
     "It's going to be a wonderful day!" said the Professor, looking  at the
clear, almost polished blue of the sky.
     "But what a lot of  flies there will be!" sighed Valya. "Even more than
yesterday."
     "That's nothing  to worry about!" The Professor  calmed her and rubbing
his hands announced: "Very soon there will be fewer! Decidedly fewer!"
     "Why fewer?"
     "Well, didn't you hear my mines exploding?" asked  the old man, looking
surprised.
     "I heard them," said Valya, "but the flies apparently don't worry about
your mines at all. Over there the mines exploded right amongst the flies but
they had no effect."
     "Wait a little!" the Professor  calmly stroked  his beard. "There is no
hurry! The flies are not killed at once by my mines. After a piece has stuck
into the fly, it will crawl around for five or six  hours and then it begins
to die in a very interesting way. Oh, this is well worth seeing!"
     "And these flies are already wounded?"
     "Certainly!" replied the old  man confidently. "Because  the explosions
started, if I mistake not, at earliest dawn."
     Valya pulled a rock out of  the barricade and sticking herself into the
observation post so formed started to watch the terrace.
     Huge,  hairy flies wandered past  the rocks. They went up  to the honey
pool, thrust their snouts into the honey and jostled one another.
     One of them - large with white body - sat on the overturned barrel. The
barrel rocked. The fly  flew up alarmed and  circled  around, gazing  at the
barrel from above  with huge protruding eyes. Then it  cautiously  came down
and alighted beside the barrel.
     And then suddenly  it  reared up and staggered . as if drunk. Its  legs
bent under it. It fell to the ground, flopped its heavy head on the sand and
started to die. Only its wings spread widely out still quivered slightly.
     "That's number one!" shouted Valya.
     "And that's not  the whole business either!" said the Professor.  "Wait
and see what will still happen to it."
     After  a little  while the  Professor and  the children went up to  the
barricade again.
     On the terrace in front of the cave  several flies had now fallen. Some
of  them were still  alive  - they moved; others lay with their wings spread
out and their heads drooping to the ground. They were covered with something
white just like hoar-frost. But from the body of the fly lying by the barrel
there rose up a long, thin stem with a round little hat on the top of it.
     "What ever is that?" asked Valya. "It looks like a mushroom."
     "That's just what it is - the Empusa fungus."
     Suddenly the little hat of the fungus broke off and fell to the ground.
     "A new Empusa has ripened!" said the Professor.
     "What a comic word - Empusa!" snorted Valya.
     "Hardly comic, is  it? At any  rate, it has never seemed comic to me. I
have  kept the  company  of  the  Empusa for  a long time now. It's  an  old
acquaintance of mine. A parasitic fungus. . . . One of the most useful fungi
to mankind. . . . It kills flies.
     Now that new Empusa which has just fallen on the ground will explode as
soon  as  ever  a fly gets  near to  it and it will sprinkle  the  fly  with
splinter seeds; the seeds grow up, kill the fly and throw off new mine fungi
destined to destroy more flies."
     "But if the flies do not make an appearance?"
     "Then the Empusa will not explode !"
     "Well, suppose it is a  bee and not a fly which comes near it, will the
Empusa go off or not?"
     "It will not go off."
     "You mean the Empusa won't explode when a bee comes near?"
     "These  ones  won't. But  bees also have their own parasite-fungus.  It
gets into the hives  and ruins them. Now naturally such fungi are not useful
but actually extremely harmful."
     "Clop!" sounded again on the terrace.
     The Professor stuck his head out and said:
     "There are  another five flies ready !  They'll soon  stretch out their
legs."
     And in fact the whole terrace was soon strewn with flies' corpses.
     The pathway to the lake was free.

     * * * * * *

     After dinner the Professor decided to go off along the shore to see his
famous  Carrabus. Was  it  still there? Had the wind torn it  adrift? Had it
capsized?
     He collected a coil of spiders' cords, threw  it over his shoulder  and
sticking a sharp stone in his girdle went to the entrance.
     "Now Valya, come on! I hope you will help me?"
     "Certainly I'll help, if only. . . ."
     "If only what?"
     "If there are no more flies on the terrace."
     "There are none and there won't be any," answered the old man.
     "But new ones? Won't they fly up."
     "Very unlikely. Even  if they did fly  up they would be done for  right
away. You see our whole terrace is now mined with Empusae."
     Valya comforted, moved off to the entrance.
     "But what about me?" Karik leaped up from his bed.
     "Why shouldn't you lie there? Get yourself right! We can manage without
you to-day."
     "Without me!" Karik was offended. "Now,  do you even know  what  a main
sheet is? or what the mizzen is? or the jib? or a topgallant sail?"
     "Well, well," laughed the Professor. "We have got a sea dog here."
     "Neither  a dog nor a  sea dog but  I  do  understand  something  about
ships?" replied Karik, with pride. He had learnt these nautical terms from a
sailor friend of his.
     The old  man waved his hand.  "If it's like that, you had better  come.
You won't be able to do  anything.  Only be careful - don't  injure your bad
leg."
     The travellers went out of the cave.
     "A real massacre!" said the Professor, picking his way between the dead
flies.
     Valya carefully  made a  wide arc round the  flies, looking sideways at
the  corpses. Although the flies were dead, yet .  . . all  the same  it was
better to keep well away from them.
     "Stop!" shouted Karik suddenly.
     The Professor and Valya quickly looked towards him.
     Karik stood near a huge fly which lay with its wings spread wide apart.
     "What is it, Karik?"
     "Look," answered Karik, lifting a transparent wing of the fly with both
hands. "A sail! Do you see?"
     "I see! Of course, I see!" rejoiced the old man.
     He went over  to the fly  and  having moved  its taut,  stretched wing,
said:
     "It will make an excellent sail! We'll use it!"
     Taking the sharp stone  out of his girdle, the  Professor got up on the
fly and with a strong blow cut off the wing.
     The wing fell at Karik's feet.
     "One  is too small," said Karik, lifting up  the wing and examining it.
"This would only do for a jib. But we shall need a sail for the mainmast."
     "Why not for the mainmast too?" said the Professor.
     And  he  started deftly cutting  off wings  with  his sharp  stone  and
throwing them  down. The children  collected the  wings  in  a heap. At last
Karik said:
     "That should surely be enough!"
     They quickly made a stack of wings one on top of the other:
     the wings rumbling just like drums.
     The  Professor  attached his cord to the bottom wing  and threw it over
his shoulder and hauled the heavy load after him to the beach.
     "There, you see," said Karik, cheerfully, steadying the wings with  his
hands. "I, of course, knew beforehand  what  sails would be necessary. I had
only to look at these and I saw what could be done with them."
     "Good enough! Good enough!" laughed the Professor. "Pat yourself on the
back! But  you had  far better hold on  to those wings and see that we don't
lose half of them on the way."
     The travellers dragged the heavy load to the beach.
     In the quiet inlet the famous Carrabus was  lying at her moorings.  Her
curved bow was reflected in the  still, calm, blue water. Her sides at their
lowest point were practically level with the surface of the lake. Around the
tall mast stood the white barrels of honey.
     "A real ship," said Karik, "it only wants sails now."
     "And sails she will have very soon," responded the old man.
     Having pulled the flies' wings on board the ship the party proceeded to
rig her.
     Karik clambered up the mast.
     "Come on now! Give me one of the  wings and the  cord!" he shouted from
aloft.
     The work went ahead furiously.
     The Professor handed  up the wings. Karik lashed them  to the mast, one
above  the  other, and  soon the whole  mainmast was hung  with  transparent
sail-wings.
     The wind started to play on the wings.
     The sails of the Carrabus started to flap.
     Then suddenly the stake  to which the mooring rope was fastened started
to crack and broke off.
     "Oh, dear!" shouted Valya.
     The Professor without saying a word jumped into the water.
     "What's happened?" asked Karik, from aloft.
     No one answered him. Then  he, having stuck his head between two wings,
saw that the old man was standing up to his waist in water and purple in the
face with exertion was towing the ship towards the shore.
     "Did the rope come adrift?" he shouted down.
     "Yes and no ! A wasp bit through the stake!"
     "A wasp?" he asked. "Why is it such a fool as to eat a reed cane?"
     "It certainly is no fool," said the Professor, winding the mooring rope
round a thick  stump. "The wasp does  not eat reeds, it makes  paper out  of
them for the construction of its nest."
     Valya opened her eyes wide.
     "Wasps know how to make paper?"
     "Yes. They  and mankind  have both learnt how  to  make paper from wood
pulp,"  replied  the  Professor,  and gave the children a  whole  lecture on
wasps, wood pulp and on the ancient, long-forgotten discoveries.
     "There was a  time," he continued,  "when paper  was prepared only from
rags. The scientist, Jacob Christian Sheffer, who lived a hundred years ago,
when investigating the lives of insects learnt from them how to  make  paper
from wood  pulp. It was when  he was examining a wasp's nest on one occasion
that he noticed that it was made of a material which resembled cardboard. He
observed the work of the wasp. It was then that Christian Sheffer discovered
that  the wasps  chew pieces  of  wood  into pulp and from this pulp prepare
excellent paper.
     "But at the time of Shelter's discovery  no one  paid any  attention to
it.
     "Fifty years passed. Another scientist, Keller, reminded people of  the
discoveries  of Sheffer and  reminded them just at the right time. Paper was
in great demand and the supply of rags was insufficient. . . . So they tried
to make paper like the wasps  out of wood pulp. . . . To begin with, nothing
came of  it but afterwards the methods  were  improved and success followed.
Since that time the bulk of the paper we use is prepared from wood pulp.'
     "Oh,"  said  Valya, having  endured the lecture. "This means that there
must be wasps about. Let's be quick in going home."
     "It certainly is high time to go home," agreed the old man.
     The travellers returned to the cave.

     * * * * * *

     In the morning whilst it was  yet  hardly light  they rolled  the  last
barrels  of honey on board, transferred  their mattresses  and brought their
firefly eggs with them.
     One egg Karik lashed to the top of the mast like a steaming light.
     He now hustled about more than the others.
     Running along the ship he shouted in a real sea captain's voice.
     "Heh. You on the poop! Haul in the sheets!"
     "But what is the poop?" asked Valya, timidly.
     "Why,  where you are standing -  that's the poop. It's the same as  the
stern. Heh! Haul in the sheets. Ship's boy!"
     "But what are the sheets?"
     "Sheets - those ropes."
     "And is there  any reason," asked the Professor, "why  the stern should
not be called the stern and the sheets should not be called - ropes?"
     Karik only laughed.
     "Well,  call  them  what you  like.  But  I shall in  future call ants'
cocoons ants' eggs."
     The Professor clenched his hand.
     "No,  no,  not  eggs,  cocoons!  I'll  somehow  master   your  nautical
gibberish, only please don't call cocoons eggs."
     Karik again started to throw his weight about.
     "Let  go the falls," he shouted in a thunderous voice. "Topmen to their
stations. Up ensign!"
     The Professor cast off  the  mooring  rope and coiled it neatly  in the
stern. Valya hauled in the sheets.
     The Carrabus was now ready for setting sail.
     "It would  be the proper thing," thought  Karik, "to fire a salute from
our guns before leaving harbour."
     Unfortunately there were no guns.
     Karik went from one end of the ship to the other, moved  the barrels to
correct the list of the ship, inspected his crew and spat overboard.
     It was a moment of triumph.
     Karik raised his hand. .
     "Attention !"
     The crew returned their captain's gaze.
     "Course south-west!  Full speed ahead. Shiver my timbers and splice the
mainbrace!"
     "Aye,  aye,  sir!"  barked  the Professor  at  the top  of  his  voice,
cheerfully winking at Valya.
     Valya slackened the sheets. The wind started to fill the sail.
     The Carrabus pitched slightly, rolled her mast from side  to side a few
times  as if considering whether  she would  set out or stay in harbour  and
then slowly started to move away from the shore.
     "Full speed ahead!" shouted the brave Captain.
     . . . The wind blew.
     White horses  now started to top the waves  with  foam. The ship rolled
and swept  along  on  the  waves.  Warm spray beat in the faces  of  the sea
voyagers. The fine ship heeled over and cut through the water.
     Around the Carrabus  strange  living things kept popping up everywhere.
They  overtook the ship, leaped  out of the water  and  frisked  about  like
dolphins.
     One  creature  resembled a  rabbit but with  stag's  antlers, and quite
transparent  swam  for  a  long time  beside  them and  would not  leave the
travellers' ship.
     It was possible  to  examine this devoted attendant  of the  good  ship
Carrabus  in some  detail as its  insides  could be clearly seen through the
transparent envelope of its body.
     "What is it?" asked Valya.
     "It is  a very ordinary Sida crystallina," answered the Professor, "one
of hundreds of water fleas."
     Valya hit the water flea on the head with a stick. It disappeared.
     Abeam crossing the track of  the ship something  very like  a submarine
was surging along. The  creature was swimming  under  water, but  its tracks
could be seen on  the surface. This creature  very nearly collided with  the
Carrabus, but at  the very  last  minute  turned  suddenly to starboard  and
quickly disappeared deep down in the water.
     "What was that?" whispered Valya, frightened.
     "That, now," replied the old man calmly,  "was a very common snail. The
pond snail!"
     "A water snail?"
     "Ay, ay!"
     "How does it get through the water?"
     "Well,  that  question,"  said  the Professor, smiling, "was one of the
most difficult to solve; however, it has been answered brilliantly. The pond
water snail travels, strange as it may seem, head downwards,  stretching out
its  solitary leg it exudes through it a mucous or slime on  the surface  of
the water. This  trail  attaches itself  to the  foam on  the  water and  is
carried along with it as if attached to a raft."
     "But in this case it can't see."
     "It sees splendidly. Because its eyes are in its foot!"
     "Pretty hot stuff that!" Karik was excited.
     "Mm -  yes!"  gruff-gruffed  the  old  man.  "Is there  anything to  be
surprised at?  We have already met  queer animals  which have no mouths  and
animals which hear  with their legs, but now you are surprised by a creature
which sees with its foot. But all these  are dull trifles compared with what
I could tell you about strange creatures.  These animals,  all of them, live
beside us. This is no  fairy story by Andersen or Grimm. These creatures are
found in the best, the  most  marvellous story of  all which is .  . . Life.
However, I am so often giving  you lectures  that I am afraid you will begin
to think  that I didn't come  to fetch you home but  to teach  you biology..
Let's sing something for a change, my dears !"
     Now this  proposal really  did  upset  the  children.  The  Professor's
stories, although at times somewhat boring, it was, quite possible to listen
to, but  the ol