THE ENTOMOLOGIST. 555 



taken on the same clay, or of the same age on different days. 

 Of a given number thus gathered I should expect the sexes 

 to be about equally divided, and we in reality find that of the 

 one hundred and seventy-one larva?, particularly mentioned, 

 the sexes are almost equally proportioned in number, eighty- 

 eight males and eighty females having been obtained, and a 

 {aw chrysalides (which, as we shall presently see, would most 

 likely be females) perishing. In Anisota, on the contrary, the 

 eggs are deposited in batches, and it is more easy to get a 

 number of larvae of the same age. Mrs. Treat's experience 

 with her thirty-three larvae is quite opposed to mine with the 

 same species. 



Mrs. Treat does not tell us whether she did or did not use 

 any discretion as to the size in selecting her intended males 

 and females ; and this is a very serious omission, as, by the 

 criterion of size alone, among larvae of the same age, the 

 sexes in many species may be separated with considerable 

 certainty. 1 regret also that she has not specified at what 

 age, and whether always at the same age, the treatment of 

 "feeding-up" and " shutting-off" was begun, though we may 

 infer, from what is said, that it was after the last larval 

 moult. 



Mrs. Treat speaks of keeping larvae eating beyond the 

 period of pupating, or rather of preparation for that change, 

 and of " starving" them, as though there was hardly any limit 

 to these processes. Analysed, what meaning do these ex- 

 pressions convey ? Very little. They are deceptive ! Most 

 Lepidoplerous larvae, in a state of nature, would come under 

 the head of "feeding-up," as they usually have an ample 

 supply of food at command, and eat their fill. While, there- 

 fore, it is perfectly possible to stunt such larva) by furnishing 

 them with a scant s^upply of food, and thus to prolong the 

 period and diminish the amount of their development, it is 

 utterly impossible, in the great majority of cases, to get them 

 to eat after they once commence to prepare for the chrysalis 

 slate. This is my firm conviction, after ton years of pretty 

 extensive insect-rearing; and I think that most experienced 

 insect-raisers will agree with me. If disturbed after prcj)aring 

 to pupate, most larvae will repeatedly renew similar j^repara- 

 tions, but if too often frustrated they will cither transform 

 without the proper preparation or die. They are, doubtless, 



