THE STATE ENTOMOLOGIST. 145 



interest in Entomology, and is an excellent observer. It were greatly 

 to be wished that more of our ladies would interest themselves in 

 such studies, for we have altogether too few Madam Merians. 



In about five days after deposition, the egg hatches, and the young 

 larva as soon as hatched usually turns round and devours its egg- 

 shell ; a custom very prevalent with young caterpillars. At this stage 

 it differs considerably from the mature larva ; it is perfectly cylindri- 

 cal, about 0.12 inch long and much of a thickness throughout. The 

 head is jet black and polished; the color of the body is pale green- 

 ish-white with the anterior and posterior horns showing as mere 

 black conical points, and with two transverse-oval black warts, nearer 

 together, on the first joint. It is covered with minute black bristles, 

 arising from still more minute warts, six on the back and placed four in 

 a row on the anterior portion and one each side on the posterior por- 

 tion of each joint, (Fig. 64, f); and three on each side, one in the 

 middle of the joint, and two which are substigmatal, pos- 

 teriorly, (Fig. 64, e.) There is a sub-triangular black spot on 

 the anal flap, the legs are alternately black and white and the stig- 

 mata are made plainly visible by a pale shade surrounding them. 

 When the young worm is three or four days old, a dusky band ap- 

 pears across the middle of each joint; and by the fifth or sixth day 

 it spins a carpet of silk upon the leaf, and prepares for its first moult. 

 After the first moult the anterior horns are as long as the thoracic 

 legs, the posterior ones being somewhat shorter ; the characteristic 

 black stripes show quite distinctly, but the white and yellow stripes 

 more faintly. After this it undergoes but slight change in appear- 

 ance, except that the colors become brighter and that at each suc- 

 cessive moult the horns become relatively longer. There are but 

 three moults.* and the intervals between them are short, as the worms 

 frequently acquire their full growth within three weeks from hatch- 

 ing. 



Some persons may be curious to know how the larva acquires 

 longer horns at each moult. The explanation is simple. During 

 each period of growth the skin which is to serve for the next period 

 is forming and perfecting under that which at the the time serves 

 the worm. Upon this inner skin and beneath the outer one, the horns 

 are also developing, and when the outer skin has become useless and 

 the worm, after a short period of rest and fasting, bursts it near the 

 head and works it off, the old horns go with the old skin and the new 

 ones appear as mere stubs. The new skin is now very fresh and 

 moist, and no sooner is the old skin off than these soft stubs begin 

 to swell, and it is then easily seen how wonderfully the long horns 



*I do not include the last moult by which the larva is transformed to the chrysalis. Some 

 persons in counting the different moults that larvae pass through, are content with counting the 

 heads that are shed. Whenever this method is relied on it should be borne in mind that the heads 

 really increase in size between each moult, though not in proportion to the increase of body. Thus, 

 in the present species the first head is considerably larger when shed than it was when the larva 

 hatched, and though appearing uniformly black when hatched, it shows the usual white marks 

 more or less distinctly when shed. 

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