The Larva and the Nymph 



several days on end, without afterwards find- 

 ing a trace of moisture inside them. Com- 

 pare the Sphex' cocoon, with its manifold 

 linings, which are so well-adapted for the 

 protection of the larva in an unprotected 

 burrow, with the cocoon of the Great Cer- 

 ceris, lying under the dry shelter of a slab of 

 sandstone and at a distance of eighteen or 

 twenty inches underground: this cocoon has 

 the shape of a very long pear, with the nar- 

 row end lopped off. It consists of a single 

 silken wrapper, so thin and fine that the larva 

 shows through it. In my numerous ento- 

 mological investigations, I have always seen 

 the larva's industry and the mother's thus 

 making good each other's deficiencies. In a 

 deep, well-sheltered abode, the cocoon is of a 

 light material; in a surface dwelling, exposed 

 to the inclemencies of the weather, the cocoon 

 is stoutly built. 



Nine months elapse, during which a task is 

 performed wherein all is mystery. I skip 

 this period, filled with the dead secret of the 

 transformation, and, to come to the nymph, 

 pass at once from the end of September to the 

 first days of the following June. The larva 

 has cast its withered slough; the nymph, that 

 transitory organism, or rather that perfect 

 105 



