146 ox VISIBLE AND INVISIBLE CHARACTERS IN SILKWORMS. 



of the visible colour character, show great complications. The 

 univoltine layings which appeared in tlie generations after F^ in 

 the multivoltine Xistri 2 '-^^^*^ univoltine Ital.-Jap. S cross, and 

 the multivoltine layings which appeai'ed in the recipiocal cross, 

 show that the maternal parents are dominant in the univoltine 

 and multivoltine character respectively, and that these characters 

 ivere inherited from the paternal grand-parents in which they luere 

 dominant characters. So these recessive characteis in males 

 appear to become dominant when inherited by the females. 

 Either the female sex is in some way closely associated with the 

 dominance of the multivoltine and univoltine characters, or there 

 is some factor present in the male which makes the univoltine and 

 multivoltine characters lie latent, but does not hinder them from 

 being handed down to the offspring, the females of which may show, 

 in a dominant form, the latent cbai'acter of their paternal parent. 

 The inheritance of the invisible vmivoltine and multivoltine 

 character does not appear to be quite Mendelian ; however, it 

 may he that the sex-limited descent afiects the inheritance, and 

 there is really no failure in the segregation of the unit characters 



Bibliography. 



Bulletin of the College of Agriculture. — Tokyo Imperial Univer- 

 sity, Japan, 1906, Vol. VII. "Studies on the Hybridolog}' of 

 Insects '' : K. Toyama. 



" Sulla Riproduzione degli Incroci e su aleuni cai-atteri ei-editai-i 

 che presenta la, Sericaiia Mori in relazione alle leggi di Mendel '' : 

 E. Quajat. 



"Mendel's Principles of Heredity": W. Bateson. 



" Breeding and the Mendelian Discoveiy " : A. D. Darbishire. 



