78 SILKWORMS. 



from the cocoon before the emergence of the moth, which is 

 thus deprived of the leverage the body of the cocoon affords in its 

 efforts to drag itself from the enveloping skin. The struggle thus 

 becomes protracted, and the body, begins to harden before it is 

 entirely freed. Hence the insect is sure to become a cripple, its 

 wings not being duly unfolded ; the same result is produced when 

 the newly disclosed moth has not room enough to expand its 

 wings, and, in fact, any interference at the critical time of its 

 emergence from the pupa case is likely to cripple the insect, in 

 consequence of the softness of all its parts. Cripples should be 

 destroyed, and not allowed to perpetuate their race, even if they 

 are inclined to do so. 



By far the most extraordinary of all malformations or monstro- 

 sities on record, is a case reported in the " Entomologist " for 

 September iSSi, by Mr. E. Kay Robinson. In this instance, 

 the insect only partially emerged from the pupa case, and as 

 much of the contents as was revealed showed two moths, a male 

 and a female, in the one pupa, which again originated from a 

 single caterpillar. This is remarkable enough, but the marvel is 

 heightened by the fact that, though the chrysalis itself was of the 

 usual shape, the moths or so much of them as was formed were 

 upside down, that is, their tails were in the position that ought to 

 have been occupied by the head ! But Mr. Robinson had better 

 speak for himself. He says : " The larva, among a small family of 

 six, seemed in no way remarkable, and the pupa was certainly of 

 the ordinary size and shape. In fact, there was nothing noticeable 

 about any of my six silkworms in their immature stages, except 

 that they appeared to get very ill when I fed them on lettuce, and 

 were one and all rather stingy in the matter of silk. Five emerged 

 in the way in which a proper-minded silkworm should, but the 

 sixth, to my astonishment, seemed to have so far forgotten itself 

 as to endeavour to come out tail first from the pupa. My surprise 

 was increased by observing later on that there was evidently 

 another imago of a different sex in the same pupa, equally anxious, 

 and equally unable, to distinguish itself by emerging upside down. 

 From July i4th to 2oth they solemnly waved their abdomens in 

 the air without cessation, and then the female tail settled down 

 to the business of life, and laid five eggs, apparently expiring on 

 the 22nd of July. Roused, however, by a stern sense of duty, 

 she revived on July 24th, and laid another egg; then I think she 

 really died. The male is still July 26th alive, though not 

 active ; he seems resigned to his fate of partial imprisonment for 

 the rest of his mortal life. . . . The changes implied in this 

 arrangement are so enormous as to stagger belief, were it not that 



