March. ii.i6.i A'. FU.IIIAM) Y. KL'WADA-.—Oy TJfE (/OMPUSJTION 87 



sidcr the remarkable example oi' the ])resence of triplicate 

 factors for the one red colour of the grain of a special kind 

 of wheat studied by Nilsson-Ehle ; and this triplicated presence 

 of factors {RJ\..I\:;) for the red colour was used to explain the 

 all different gradations of the intensity of the red colour 

 among F.-generations or in the seeds of Fj-plant. To illustrate 

 this he tabulated the different classes of factorial compositions 

 about the number of red factors. According to him, the number 

 of the red factor R varies among red classes from one to six. 

 This means that he ignored the fact of triplicate nature of 

 endosperm cells. In fact the number of i?s or red factors should 

 vary according to the new formula, from one to nine, instead 

 of one to six ; and the result will be more in accordance with 

 the fact of all possible gradations of red colour of the wheat 

 seeds in question, 



A revision, under the application of the new formulae, of the 

 results of genetic study with respect to quantitative characters 

 as percentages of sugar, starch, and other substances contained 

 in the seeds, is highly desirable ; for such studies concerning 

 chemical characters, as has been undertaken by Pearl and 

 Bartlett^', are very important to the science of genetics. 



Certainly the use of this formula is not to be restricted to 

 Zea and Triticum, but should be extended to the angiosperms 

 in general,'' and at the same time it must be borne in mind that 

 it is limited to seed-characters belonging to endosperm. 



Pigments of the seed- — The difficulties of interpretation of 

 zygotic distribution, concerning colours on a cob of di- and 

 polyhj'brid maize plants, which one may encounter, are caused 

 by several conditions. One of them which is due to inappro- 

 priate construction of zygotic formulas can be elliminated by the 

 correction of the latter as has been just pointed out. We have 

 to note here, however, another condition, that is, the occurence 



1) Zeitsclir. f. ind. Abst.- und Vererbungsl. Bd. 6. 1911. pp. 1-28. 



2) For each particular case, where the endosperm is known as other than tri- 

 ploid, e.g., liaploid, diploid, or a polyploid, tiie factorial formula mu-^t be constructed 

 accordingly. 



