196 THE PHILOSOPHY OF BIOLOGY 



as quantitative differences in the value of the same 

 character. 



Such a suppression of a character is not really a 

 loss. An organism belonging to an elementary species 

 in which, say, monochromatic flowers are usually 

 produced may produce flowers which are striped. 

 The progeny of the plant may still produce mono- 

 chromatic flowers, but we must think of it as also 

 possessing the potentiality of producing striped flowers. 

 In the terminology of Mendelism the characters are 

 dominant and recessive ones. 



In discussing Mendelian varieties we consider the 

 manner in which two contrasting characters — one 

 present in the male parent and one in the female — 

 are transmitted to the offspring. The characters in 

 question may be the tallness of the male parent and 

 the contrasting shortness of the female ; or the brown 

 eyes of the male and the blue eyes of the female ; or 

 the brown skin of the female parent and the white 

 skin of the male one. These characters may be 

 inherited in two ways : either they may be blended 

 or they may remain distinct in the offspring. The 

 children of the brown mother and the white father 

 are usually coloured in some tint intermediate between 

 those of the parents. The mulatto hybrid is fertile 

 with either of the parent races, and again the off- 

 spring may take a tint intermediate between those of 

 the parents, and so on through a number of generations. 

 But somewhere in this series the concealed or recessive 

 brown colour may appear in all its completeness, 

 showing that it has been present in the organisations 

 of all the intervening generations. The progeny of a 

 tall male parent and a short female parent are not, 

 in general, intermediate in stature between the parents ; 

 some of them may be tall and others short. The 



