THE YOUNG SCIENTIST. 
331 
flies, for sueh they proved to be. Well, I 
knew that every caterpillar that had been 
struck by them would never develop into 
an attacus moth, though he would spin 
his cocoon and change into a chrysalis. 
This may seem contradictory, but it must 
be understood that when a caterpillar is 
struck by an ichneumon the fly drives his 
ovipositor deep into the flesh of the cat- 
erpillar, the result being that an egg of 
the ichneumon is deposited. When the 
caterpillar slips off his skin, after spin- 
ning his cocoon, this egg, passes into the 
body of the chrysalis, on which it 
lives. In the spring of the year, 
about the time the chrysalis would 
have changed into a oecropia moth, 
the now perfect larva of the ichneu- 
mon is strong enough to cut its way 
out of the silk material of which the 
eocoon is composed, and develop 
Into a perfect ichneumon fly. To 
save my pets from destruction, I cov- 
ered the elder branches with mos- 
quito netting. In course of time 
numbers of the caterpillars began to 
act sluggish, and refused food, and 
I feared that they were sick; bat 
such was not the case; they were 
going through a preparatory rest 
before commencing to spin their 
eocoons. Now I was very anxious 
to learn and understand all about 
this exceedingly interesting /oper- 
ation, so I devised a scheme by 
which I could imprison them, and at 
the same time have them directly 
under my eye. Procuring a starch 
box^ which consisted of light wood^ 
I withdrew the sliding top, and also 
removed the bottom, as shown in 
Pig. 1. To the upper four corners were 
attached four strings; these strings 
were gathered a yard above the box, 
as shown in the illustration. At the 
point where the four strings met was at- 
tached the single string, a, and to this 
string was attached a cone of heavy and 
highly calendered writing paper, as 
shown at b. The intention of this cone 
was to prevent the caterpillars from pass- 
ing up the string a and escaping. I never 
knew one of my caterpillars to attempt 
to make his escape by dropping off from 
his place of imprisonment; they seemed 
to instinctively know they are of so fleshy 
a nature that such a proceeding would be 
certain death. Inside and outside of the 
box were fastened numbers of small elder 
branches, and on the top of the box was 
constructed a cone-shaped mass of the 
same material, which, to more securely 
hold it together, was tied to the four con- 
verging strings. This odd-looking struc- 
ture, after being completed, was then 
charged with ripe cateri:>illars. At first 
they ceaselessly wandered over the 
Fig. 2. 
branches, and up the st rings to the paper 
cone; but at last the promptings of na- 
ture forced them to succumb, and they 
began to throw tlieir silken webs, to spin 
their cocoons. Was I greatly interested ? 
Well, yes. Did I reach the office late, 
very late, of mornings ? Yes. Did my 
employers wonder what was the trouble ? 
Yes, they did ; and the leading editor in- 
quired as to what new hobby I had got 
astride of tljistime? I frankly told him 
I had mounted and was riding tandem 
some two hundred caterpillars. Now, be 
