K. TOYAMA 381 



In the crossings above quoted, we compared the reciprocal F^ eggs 

 with those laid by pure maternal breeds in each case, and came to the 

 conclusion that the colour-characteristics of the egg are governed by 

 those of the female parent. As far as our experiments went, it is very 

 difficult to distinguish between these F^ eggs and those laid by pure 

 maternal breeds, even to the eye of experienced breeders the line of 

 demarcation was indistinguishable, except in the case of albinotic 

 matings. 



As to the albinotic matings, the case is rather different from that of 

 the coloured matings, since the eggs laid by albino females mated with 

 coloured males sometimes were more or less influenced by the male 

 characteristics and sometimes shewed no male influence. In the Chusu 

 albino matings we often obtained pure white Fi eggs, while in the 

 orange albino these maternally characterized eggs were rarely found. 



Now then, we may draw the conclusion that most of the egg-colours 

 which are commonly met with in various breeds are maternal in 

 inheritance, in spite of the origin of these different colours being due 

 to the pigments which are deposited in the serosa. In Chinese, 

 European and in some green breeds the green colour of the shell may 

 help the production of these greenish shades, but it is not the chief 

 cause of the green colour. 



Concerning albino breeds which gave rise to more intricate series of 

 results when crossed with other coloured breeds, we shall describe them 

 in the second contribution of this subject. 



From the series of experiments above mentioned, we know that all 

 the colour-characteristics of the silk-worm egg are maternal in in- 

 heritance with the exception of the albino, in which the recessive 

 uncoloured characteristic of the female parent is sometimes more or less 

 influenced by tiie dominant coloured male. We must not forget, how- 

 ever, that there are breeds whose egg-characteristics behave exactly as 

 other normal Mendelian characteristics do. We shall now describe 

 a case of this kind studied by us. 



Series 5. Inheritance of the " Cnmson-egged" Breed. 



In the spring of 1909 we obtained, through the kindness of 

 Mr J. Ariga of the Nagano district, two batches of eggs laid by a 

 divoltine breed. This breed is characterized by the special colour of the 

 egg which is a clear crimson-red. It is one of the most strikingly 

 coloured eggs we have ever had. In one batch (No. 5) we found 

 30 normal coloured eggs and in another (No. 20) only two normal eggs, 

 all the remainder were crimson-red. 



