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INSECT STUD} 159- 



"worms" are then only a quarter of an inch long and have round, 

 red-brown heads, large in proportion to their bodies, which are 

 yellow with side lines of dark spots. 



But they eat, and eat, and eat, till their skins become too 

 tight to live in and are cast off or molted, at intervals, till they 

 have become changed four times. They drink too, so it is 

 necessary that when fed, their leaves should be not only 

 fresh but dipped in water. After the first molt their bodies be- 

 come green, blue-green above and yellowish below the lateral 

 line, with orange tubercles. The segments of the body are 

 deeply and sharply cut. When full grown, polyphemus larvae- 

 are about three inches long and as thick as a grown person's 

 thumb. The creature has a way of drawing itself up with the 

 front part of the body lifted, and remaining motionless for a 

 long time, looking from the side very much like a tooth-edged 

 leaf. Undoubtedly it often escapes notice thus and one won- 

 ders whether it has any realization of the fact. 



In nature, caterpillars have many enemies. Xot only 

 are they tidbits for birds and squirrels, mice and bats, but fun- 

 gous diseases attack them, parasitic flies deposit eggs upon or 

 within their soft and juicy bodies, where they hatch and feed 

 upon the living host, slowly destroying it. This is well, for 

 otherwise their numbers would so increase in the land that man 

 would be unable to cope with them. But it follows that when 

 one wants adult specimens without blemish, the best way to 

 secure them is to rear them for oneself, away from the reach 

 of all such harm. At the same time one learns the full life 

 history of the insect. 



Any box close enough to keep the caterpillars from escap- 

 ing will do for a feeding-cage. For the sake of observation, 

 one of its sides should be of glass. A large glass battery jar 

 covered with cheese-cloth or wire netting makes an excellent 

 cage, for in it leafy twigs may be placed in vials of water to 

 keep them fresh and the crawlers may feed in full view from 

 all sides. 



Pupils should be required to take very full notes, putting 

 down nothing to which their own eves have not testified. Such 

 points as the length of time the larvae feed before the first 

 molt; how they attach themselves to a support while casting 

 the skin; how long they rest while molting: any changes of 

 color, size and form caused by the molts, should be noted and 



