﻿NOTES ON SILK-PRODUCING AST) OTHER BOMBYCES. I2t 



cocoons, all extremely small, again male and female moths 

 emerged, about half the size of ordinary specimens. I do not 

 know whether the larvae of these promethea were bred in captivity, 

 but I should think so considering their small size. 



In nature, however, there are dwarfed individuals in all 

 species of insects and other animals, and this has nothing to do 

 with the quality or quantity of food consumed, as they live side 

 by side with, and on the same food as, their brother giants. It 

 is a freak of Nature, who delights in creating these dwarfs and 

 giants, with all the intermediate sizes between. 



With respect to small-sized insects, I may also say that I have 

 frequently found small moths possessing more activity and vitality 

 than larger ones, just as we find some small men stronger than 

 big men. 



Taking my leave of the dwarfs and the giants, I will say a 

 word or two about young larvae. My belief is that a larva, if it lives, 

 must produce in course of time a male or a female perfect insect, 

 independently of the quantity or quality of food it may have 

 consumed. There are two different kinds of larvae in each 

 species. With some, size alone seems to be the only difference, 

 but in others there is a marked difference ; for instance, in Actias 

 luna from N. America, the smaller larvae in the first stage have 

 longitudinal lines all along the sides of the body ; the larger 

 larvae, on the contrary, are all pale green, without any markings 

 at all. In all probability the larger larvae produce the female 

 moths, the smaller ones the males. 



After this digression, of which I had not seen the length at 

 the outset, I will pass to the remarks I have to make on the silk- 

 producing Bombyces I received during the last few years. 



From Assam every year, in winter and spring, I had large 

 quantities of Anther '&a assamensis sent to me, but never could 

 obtain a single moth. This year over 400 were sent, all the 

 moths having emerged on the voyage or died in the chrysalis. 

 Some of the moths appeared to have emerged only a few days 

 before their arrival, and this shows that there would be a possi- 

 bility to receive the cocoons before the emergence of the moths, 

 if they were sent in small boxes by sample post, going overland 

 like the letters, instead of sending them in large boxes by parcel 

 post, which takes a fortnight or more longer. 



Another species, sent also from Assam, was Attacus ricini, the 

 cultivated A. cynthia. This species is still worse to travel, the 

 moths emerging in about a fortnight or three weeks ; therefore 

 the cocoons were tied to strings laid across the boxes, to give 

 room to the moths to emerge, pair, and lay their eggs, but I found 

 the young larvae hatched and dried up. 



To obviate this rapid emergence of the moths, my cor- 

 respondent in Assam placed in some of the cases A. assamensis 

 larvae, which were just beginning to spin, thinking by so doing 



ENTOM. — APRIL, 1890. K 



