226 lock: 



have more characters in common with either grand-parent. In 

 the absence of evidence it would be unwise to labour this 

 point further. 



Among other phenomena of special interest, we may briefly 

 recall in conclusion the strictly intermediate nature of the first 

 crosses between species. This may be contrasted with the 

 apparent dominance shown by a limited number of (possibly 

 varietal) characters. 



It is not suggested, however, that this classification (due to 

 de Vries) holds good with any degree of strictness, and it seems 

 to be quite clear that segregation frequently takes place in 

 cases where dominance is absent. 



A curious case which affords an exception to the general 

 rule of an intermediate F 1 is worth recalling. So far as can 

 be ascertained from the evidence available the form E* 

 appears to be a recessive type. This tjrpe is specially remark- 

 able inasmuch as a whole series of external features seem to 

 behave in heredity as if they depended upon a very limited 

 number of internal factors. It is suggested that two principal 

 factors are concerned, one for dwarf ness and one for the shape 

 of the flowers. If this anticipation proves correct, it appears 

 that in some cases the inheritance of shape and habit are much 

 simpler matters than would have been expected at first sight. 

 It is hoped that it may be possible to investigate further the 

 inheritance of this remarkable type, which exliibits two further 

 points of interest in its sterility, and in the suggestion of 

 incipient heterostylism which it exhibits. 



The very remarkable range of stature shown by F 2 plants 

 in certain cases is noteworthy — far transcending in both 

 directions the dimensions of the original parents. 



F 2 from crosses with N. forgetiana showed a remarkable 

 range of colours, which at first sight certainly suggested an 

 explanation by some such formula as that put forward by 

 Bateson in his first report to the Evolution Committee of the 

 Royal Society (1902) to describe the complex phenomena 

 shown by sweet peas. There is no reason for supposing that 



* Of unknown origin, but supposed to be an offsboot of N. langsdorfii 

 (see p. "ill). 



