94 
PLANTS AND INSECTS 
spread their leaves out and expose a. large area to the air and sunshine, 
and the amount of moisture given off thereby can be replaced by that 
taken in at the roots. But in order to survive in arid regions the cactus 
must be adjusted to its environment. It must be so constructed as to 
prevent any unnecessary loss of water contained in its tissues and to 
retain all the scanty supply which reaches them. The body of the plant 
contains a large amount of water-storage tissue which retains Water with 
great tenacity. The amount of surface exposure is small and in most 
species the leaves have become reduced to mere spines and prickles, 
while the stems have become fleshy, sometimes resembling leaves in 
shape. The flowers are often brilliantly colored, and the fruit of some 
species is edible. 
HOW I CAUGHT A BUTTERFLY 
O NE day in the early autumn the postman left at my door a small 
square wooden box. The cover was thickly perforated with small 
holes. This suggested that on the inside was some manner of life which 
required air to breathe. I opened the box and poured the contents out 
upon the table. And lo! a bright-colored, wriggling, twisting worm 
greeted my sight. 
It was about four inches in length and about three inches in cir¬ 
cumference. It had more than eight pairs of legs. This left no doubt 
as to its correct classification. We quickly assigned it to its proper name, 
* 1 Caterpillar. ’ ’ 
This we knew was his first age of existence after leaving the egg. 
In that state it is called the larva. 
I had been expecting and even anxiously looking for the coming 
of this interesting little visitor. Also, I knew about its voracious' appe¬ 
tite, and so had prepared the most tempting dinner he could even wish 
for. Upon his table there were placed little heaps of mulberry-leaves and 
oak-leaves, and the leaves of the poplar, elm, thorn, and castor-oil bean. 
Presently, he lifted his head from side to side as though contem¬ 
plating the luscious dinner that was spread out before him. But this 
was only make-believe, as this particular species of caterpillar is wholly 
blind. He nimbled about quite lively until he came across the mulberry- 
leaves. These he greedily devoured until there was nothing left but a 
mass of stems and midveins. He stripped the pulpy mass from the 
