484 H. H. NEWMAN 



more finely branched than in F. heterochtus and larger and less 

 finely branched than in F. majalis. This is typical blended 

 inheritance. 



c. In crosses between F. diaphanus and either of the other 

 species the color of the red chromatophores of the hybrids is 

 distinctly ijiterfuediate between that of the two parental species. 



3. When numbers of integral variates are concerned the hybrids 

 exhibit a number intermediate between those of the two parents; 

 or when one parent has many of a given type of integral variate 

 and the other has none the number in the hybrids is less than that 

 in the parent showing the characters in question. The follow- 

 ing examples illustrate this: 



a. In both reciprocal crosses between F. heterochtus and F. 

 majalis the hybrids show an intermediate condition between the 

 F, heterochtus character, few or no lateral line black chromato- 

 phores, and the F, majalis character, many such cells. 



b. In the cross between F. majalis 9 X F. diaphanus d" there 

 are fewer lateral red chromatophores to the row than in F. di- 

 aphanus, although there are no lateral red chromatophores in 

 F. majalis. 



c. In hybrids between F. diaphanus and F. heterochtus the 

 hybrids have fewer black head chromatophores of the F. diaph- 

 anus type than has pure F. diaphanus and fewer black head 

 chromatophores of the F. heterochtus type than has the pure 

 F. heterochtus, yet the combined number of the two types of 

 chromatophores is, as nearly as I can determine, intermediate 

 between the total numbers of the two parent species. 



When, therefore, we analyze one set of inherited characters 

 such as the pigment characters that we have just dealt with, 

 we find practically all of the well-known modes of inheritance; 

 that characterized by dominance or even hyperdominance ; that 

 commonly called blended or intermediate inheritance ; that usually 

 called mosaic or particulate inheritance; and that which is peculiar 

 to integral variates and has sometimes been classed as a phase 

 of intermediate or blended inheritance, but which seems to me 

 to be sui generis. 



