B. T. LOWNE ON THE HYMEXOPTERA. 191 



a single larva only being developed in each butterfly's egg, several 

 are sometimes perfected in it. The young embryo escapes in an 

 unformed condition, like polynema, but remains attached to its 

 ruptured egg-shell ; this embryo becomes converted directly into 

 an unsegmented larva without any skin shedding, thus differing 

 from the types I have already described. The whole developmental 

 process is simpler than in Polynema or Platygaster, but as in those 

 genera the embryo becomes converted into a larva by the gradual 

 development of structures similar to those which are usually de- 

 veloped in the egg, a primitive fold and head lappets appear, as in 

 crustacean and insect embryos, although the larva soon assumes a 

 simple sac-like form. Soon, however, the hypodermis, or lower 

 layer of the skin of this sac-like larva becomes converted into 

 imaginal discs, and these, strange to say, form the outer integu- 

 ment of the perfect form, and are never shed. All these changes 

 take place very rapidly, and in two or three days the infected eggs 

 produce from one to three perfect Ophioneuri, instead of a single 

 lepidopteroiis larva. 



I do not know whether it will ever be possible for me to find 

 time to trace out the wonderful changes described by Herr Ganin, 

 but I feel sure that great additional light will be one day thrown 

 upon the affinities of insects by the study of these wonderful life 

 histories, and I doubt not that thousands of infected lepidopterous 

 and other eggs might be found by anyone who has the skill and 

 leisure to prosecute this research, and that the labour would be 

 repaid by the richest results. 



