32 



Mr. R. H. Lock. On the Inheritance of [Oct. 1, 



shown to bear the latent factor for maple marking ; m. is in fact almost, but 

 not quite invariably, completely latent. 



Offspring of all the 19 white plants were crossed with members of various 

 pure strains of grey and purple seeded peas, in all of which maple marks 

 were wanting. Table II shows that seven of the F 3 plants examined were 

 heterozygous in respect of the hidden factor, whilst 22 yielded only dominant 

 offspring, and seven only recessive. 



In the light of these experiments it becomes extremely probable that the 

 hidden factor — the cryptomere — comes always from the white flowered parent 

 and not from the coloured, as Tschermak supposed* in the case of several pea 

 crosses where reversion occurred in Fi, followed by the appearance of the ratio 

 9 : 3 : 4 in F 2 . 



To the behaviour of the maple character as thus described I know of no 

 exception. The purple character, on the other hand, does not, as it would 

 appear, invariably follow the simple rule obeyed by this character as exhibited 

 by the coloured native pea of Ceylon. Hitherto among extracted whites 

 derived from the cross between the Purple Sugar Pea and different white 

 strains I have been able to find no example which does not yield exclusively 

 purple offspring when crossed with grey. 



Table I. 



Note. — 57. 1, 57. 2, etc., indicate different plants of F 4 derived from seeds of the same plant 

 (No. 57) of F 3 . It will be seen that some such families include all dominant members, others 

 all recessive, and others again a mixture. 



F 4 . 







F 5 





F 4 . 







F a 





White 







t ■ A - 



N 



White 







. >_ 



\ 



parent 



Coloured 



p. 



p. 



parent 



Coloured 



m. 



m. 



number. 





parent. 



present. 



absent. 



number. 





parent. 



present. 



absent. 



58.6 



X 



9- 



2 



2 



57.1 



X 



9- 



2 



2 



62.2 



X 



9' 



3 



3 



57.1 



X 



9- 



1 



1 



63.1 



X 



9- 



1 



4 



57.2 



X 



9- 



1 



1 



64.10 



X 



9- 



3 



4 



57.3 



X 



9- 



1 



4 



65.2 



X 



9- 



2 



1 



57.7 



X 



9- 



1 



4 



65.6 



X 



9- 



2 



2 



63.1 



X 



9> 



3 



2 



65.8 



X 



9- 



2 



3 























66.4 



X 



9- 



1 



2 



5 







9 



14 



66.8 



X 



9- 



5 



2 























9 







21 



23 





Archiv fiir Kassen- und Gesellschafts-Biologie,' vol. 2, p. 672, 1905. 



