Page:A critique of the theory of evolution.djvu/90

 other type smaller splotches (fig. 37). The factors that differentiate these varieties are sex linked.

Certain types of color blindness (fig. 38) and certain other abnormal conditions in man such as haemophilia, are transmitted as sex linked characters.



In domestic fowls sex linked inheritance has been found as the characteristic method of transmission for at least as many as six characters, but here the relation of the sexes is in a sense reversed. For instance, if a black Langshan hen is crossed to a barred Plymouth Rock cock (fig. 39), the offspring are all