A STUDY OF MENDELIAN FACTORS 
IN THE 
SILKWORM, BOMBYX MORI. 
By 
YOSHIMARO TANAKA. 
Assistant Professor of Zoology, College of Agriculture, 
Tohoku Imperial University, Sapporo. 
with pi. yin. 
It can not be too much emphasized that in the study of herdedity 
experimentation is of the highest importance, but at the same time it 
goes without saying that its results must be subjected into an analysis, so to 
speak, from a theoretical point of view, for mere accumulation of data does 
not afford us a clue as to the nature of phenomena with which we are 
concerned. 
Through the investigations of Coutagne, Toyama, Kellogg, Quajat, 
Me Crack ex and Ishiwata, many interesting facts have been brought to 
light regarding the phenomena of inheritance in silkworms, the characters 
studied being larval markings, cocoon colours, wing colours in the moth 15 , 
colour and other properties of eggs 1 2) 3 4 5 , “ant” colours' 5 , and furthermore, some 
physiological peculiarities, namely voltinism 45 and .moultinism 55 . P>ut it is worth 
noting that by those authors much attention was not paid to the theoretical 
1) Melanie and whitish wing patterns. 
2) Adhesiveness and non-adhesiveness. 
3) Black and brown “ants.” (“Ant” means newly hatched larva.) 
4) Univoltinism and bivoltinism. By univoltinism we mean that the worm completes 
only one generation in a year, while by bivoltinism it is meant that two generations are 
completed in a year. 
5) Tri-moultinism and tetra-moultinism. For the sake of convenience, I use the 
term voltinism with a numerical prefix to designate number of moulting, e. g. tri-moult- 
nism and tetra-moultinism denote three and four moultings respectively. 
