m the tropics: in. 1G7 



followed in the case of several pairs of allelomorphs. 

 In other cases it appeared possible that germ cells bearing a 

 blended character were produced, though here the evidence 

 was much less complete. The specimens obtained, though 

 quite sufficient for their purpose, were comparatively few 

 and often imperfect, and Correns has himself pointed out the 

 importance of examining the proportions of the germ cells 

 in a larger series of plants, in order to discover whether those 

 departures from the expected proportion, which are found 

 in particular instances, have any special significance, or 

 whether, on the other hand, they depend simply on the 

 smallness of the samples examined. 



This then was the main object of the experiments described 

 in the present paper; and it may be stated at once that, 

 so far as the numbers examined go, the following inference 

 receives support, namely, that in the case of the allelomorphic 

 characters concerned, it was an even chance whether one or 

 the other member of a particular pair appeared in any given 

 gamete of the heterozygote examined. 



In the case of certain plant characters, which afford less 

 simple material than seed characters do,f or statistical treatment . 

 and especially in those cases where the cross-bred form showed 

 a blending of parental characters, there was doubt as to whether 

 segregation took place or not ; and in the case of the 

 character height of plants it seemed certain that blended 

 gametes were formed, though the proof of this is not so clear 

 as in the Mendelian cases, partly owing to the great sensitive- 

 ness which such a character as height shows to the effect of 

 external conditions. 



We turn now to those cases in which seed characters were 

 concerned and in which segregation was found to be of the 

 normal type. In the foregoing account the description of 

 crosses between supposed " definite " races has been placed 

 first because this appeared to be the logical sequence. But 

 in the case of the mongrel strain, of which the account stands 

 second, a considerably larger number of individual plants 



9(8)06 (10) 



