98 The Hiintmg Wasps 



buried only a few inches down in uncovered, 

 sandy ground. To judge to what extent the 

 cocoons thus varnished are able to resist the 

 damp, I kept some steeped in water for several 

 days on end, without afterwards finding a trace 

 of moisture inside them. Compare 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 Cerceris, 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 narrow end lopped off. It consists of a 

 single silken wrapper, so thin and fine that the 

 larva shows through it. In my numerous 

 entomological 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 trans- 

 formation, 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 



