LARVAL SACRIFICE 391 



youngster's stomach. In the wasp we have an egg, followed 

 by a grub that is unable, simply by eating, to become like its 

 parent. Something more radical is necessary, a complicated 

 bit of surgery which will knock down the larval house and 

 raise an imago from the ruins ! 



Thus in ten days after the larva spins its cocoon we see a 

 slight shrinking of the body. A depression just off center 

 follows. There is a tremor, ever so slight, then slowly the 

 whole perfect insect unfolds from the grub like a nascent 

 flower from its bud. It may require a million years for proc- 

 esses of evolution to become established into a train of events, 

 yet here in the course of a few days, by watching this won- 

 derful transformation from grub to pupa, we have actually 

 witnessed the ancestral form sacrificing itself to a modern 

 one! 



The processes that bring about such radical changes in 

 the insect are known as histolysis and histogenesis. The 

 former covers the breaking down and disintegration of the 

 larval tissues and the latter the building of the new body, 

 in part independent of the old material. There is little 

 known of these strange performances, yet it appears to be 

 the general belief that for the most part, the perfect insect 

 is developed chiefly from the skin cells of the larva. There- 

 fore, I shall set forth what I have been able to gather through 

 the logic of observation, about this point. I make my state- 

 ments guardedly — simply as facts that appear to have been 

 overlooked. 



A yacht is built and launched. She serves admirably 

 as a pleasure craft and is quite satisfactory for that purpose. 

 War is declared. She is commandeered by the government 

 for patrol duty and must be altered to meet new require- 

 ments. She is dry-docked, fitted with guns, more powerful 

 engines are installed and lastly she is painted battle color. 

 Later the craft appears once more upon the water. Altered 

 tremendously, the old hulk still serves the fundamental pur- 

 pose. It is much the same with the insect. The larval wasp 



