ON THE AFFINITY OF OUR WILD AND DOMESTIC SILKWORMS. 



39 



round and contains a single elongated dot of a light greenish color (fig. 12, a & 

 h). 



The cocoon is elongated oval with a slight constriction near its middle, but 

 in certain Chinese cocoons the constriction is absent and the cocoon thus assumes 

 a spindle form. The color is either white, green or yellow. The spindle shape 

 and the greenish color of a cocoon, are points of very close resemblance to that of 

 the wild silkworm. The cocoon of the domestic silkworm are very variatile in 

 size, but that of our largely cultivated race is about 33 mm. in length. 



Thus the adult of the cultivated silkworm has exactly similar characters, i.e. 

 markings, venations &c. with that of the wild form, but it differs from the latter 

 in the size and coloration as well as the lighter color of markings, but these are 

 unquestionably variations that occurred under domestication for a long interval 

 of time, and moreover, various transitional forms of the markings and coloration 

 prevalent among the adult of the domestic silkworm affords a strong evidence, 

 that the latter has been derived from the silkworm living wild still at present. 

 Further, the egg, larva, and cocoons are nearly same in forms, markings, and colo- 

 ration in both the wild and domestic forms, and the differences can be seen only 

 in a lighter coloration, more or less imperfect markings, and size. 



The above mentioned facts lead us to conclude that the domestic silkworm 

 has been derived from the wild form which belongs to exactly the same species 

 with the Theophila maiularina described by Dr. F. Moore, and the latter is 

 nothing else than the ancestral form of oui- domestic silkworm. 



