194 THE ENTOMOLOGIST. 



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 14th to 20th the_y 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 dut}^ 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. 



On the old theory that the different integuments of the larva 

 and pupa were simply so many coverings of the imago, which were 

 peeled off in turn like the skins of an onion, such an abortion would 

 be absolutely impossible ; and even our modern knowledge that 

 certain transformations occur in the internal organs of the insect 

 to accompany each change of outward appearance, does not help 

 us much to conceive the possibility of such an aberration. Between 

 the last stage of the larva and the production of the imagines in 

 the specimen in question, one of two startling operations must 

 have been formed : either each organ must have divided into two, 

 and a double set of sexual organs have developed themselves, and 

 then the whole contents of the pupa must have violently turned 

 round in the shell, so that the two heads and the two tails changed 

 place ; or else the head of the larva must have been developed into 

 two sets of anal appendages, male and female, the true legs of the 

 larva having been withdrawn. The abdominal segments of the larva 

 have become the thoracic divisions of two imagines with legs, 

 wings, &c., developed in addition, and the anal segments grown 

 into two heads with all their marvellous arrangements of palpi, 

 antennae, &c. ; and further, the liquid which the imagines excreted 

 on emerging must have been lodged in what was the head of the 

 caterpillar. The turning round of the imagines in the pupa-case 



