230 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



in a very delicate film or pellicle (amnion, see Chap. IX), which must be 

 cast off before the little creature can move with alacrity. 



By continuance of similar contracting and expanding movements which 

 freed the animal from the earth, this film in a very short time splits 

 along tbe middle of the back near the head (strictly the prothorax), and 

 is then worked off behind, and finally kicked from the hind feet in 

 a little white crumpled pellet, that has justly been likened by some of 

 our correspondents to a diminutive mushroom. These little pellets in- 

 variably lie close around the hole in the ground from which the young 

 locusts issued. The pellicle begins to split, under ordinary conditions 

 of warmth, within a minute from the time the locust is fairly out of the 

 ground, and is shed in from one to five minutes, according to circum- 

 stances. Pale and colorless when first freed from this pellicle, the full- 

 born locust is nevertheless at once capable of considerable activity, and 

 in the course of an hour assumes its natural dark gray coloring. Mr. 

 Packard observed (Eeport to Dr. Hayden, 1877, p. 634) that specimens 

 which hatched at 11 a. m. began to turn dark at 3 p. m., thus showing 

 that the time may vary ; but numerous close observations which we 

 have made on single individuals show that an hour seldom passes after 

 the amnion is thrown off before the gray color is acquired. 



'^ From this account of the hatching process, we can readily under- 

 stand why the female in ovipositing prefers compact or hard soil to that 

 which is loose. The harder and less yielding the walls of the burrow, 

 the easier will the yoiing locust crowd its way out. 



" Though the covering which envelops the little animal when first it 

 issues from the egg is quite delicate, it nevertheless, in the struggles of 

 birth, undoubtedly affords much protection, and it is an interesting fact 

 that while, as we have just seen, it is shed within a few minutes of the 

 time when the animal reaches the free air, it is seldom shed if, from one 

 cause or other, there is failure to escape from the soil, even though the 

 young locust may be struggling for days to effect an escape. 



^* While yet enveloped in this pellicle, the animal possesses greatforcing 

 and pushing power, and if the soil be not too compact, will frequently 

 force a direct passage through the same to the surface, as indicated at the 

 dotted lines, Fig. 4 e. But if the soil is at all compressed it can make 

 little or no headway, except ihrough the appropriate channel (d). While 

 crowding its way out the antennse and four front legs are held in much 

 tbe same position as within the egg, the hind legs being generally 

 stretched. Eut the members bend in every conceivable way, and where 

 several are endeavoring to work through any particular passage, the 

 amount of squeezing and crowding they will endure is something re- 

 markable. Yet if by chance the protecting pellicle is worked off' before 

 issuing from the ground, the animal loses all power of further forcing 

 its way out. The instinctive tendency to push upward is also remark- 

 able. In glass tubes, in which I have had the eggs hatching in order 

 to watch the young, these last would always turn their heads and push 



