404 Maternal Inheritance and Mendelism 



5. Thehereditaryrelationsofthosecharacteristics above enumerated: 

 as to the shape, the whitish grey is dominant towards the Japanese 

 normal which is in turn dominant to the spindle-shaped characteristic. 

 As regards the colour, the greenish slate stands first in dominancy, next 

 comes the Japanese normal brownish slate ; hypostatic to it comes 

 perhaps the blue and then reddish brown and lastly the crimson. In 

 the colours of newly laid eggs, the white is hypostatic to yellow or 

 brownish yellow. The relation between the normal and the crimson is 

 the ordinary Mendelian one, the former being epistatic to the latter. 



6. In the crimson-coloured eggs extracted from various breeds 

 or crosses, the death-rate is always much greater than that of eggs 

 from the normal, or albino breeds. Even when those three kinds of 

 eggs are laid by the same parent, the same is the case. In divoltine 

 crimson breeds, the divoltine white eggs laid by the spring or first brood 

 are much healthier than those crimson-coloured eggs laid by the summer 

 or second brood. 



7. The phenomena of inheritance observed in the eggs of the silk- 

 worm may be well compared with those observed in certain seed- 

 characteristics of plants, such as maize, peas, wheat, etc. 



EXPLANATION OF PLATE XX. 



Normal-coloured egg of divoltine " Shinkawachi." 



Reddish-brown variant from divoltine "Shinkawachi." 



Normal-coloured egg of the original breed of the whitish-grey variant. 



Whitish-grey variant. 



Blue variant derived from divoltine " Kuni-nishiki." 



Green-shaded egg from the Japanese green breed. 



Crimson-coloured variant. 



Dead egg of the crimson variant. 



Newly laid egg of tetravoltine white. 



Newly laid egg of tetravoltine yellow. 



Egg of Theophila mandarina. 

 Fig. 10a. Matured egg. 

 Fig. lOh. Newly laid egg. 

 Fig. 11. jFj eggs between female divoltine " Shinkawachi " and male Theophila 



mandarina. 

 Fig. 12. F^ eggs of the above mating. 

 Fig. 13. Batch of spindle-shaped eggs laid by a moth. 



Every figure except No. 13 is very much magnified, actual size being about 1-15 mm. 

 in length and 0*95 mm. in breadth. 



