SEXUALITY 683 



they must differ in degree of sex, or valence. In a similar way, the eight 

 types G to O (Table 10) are reduced to two sexes, -|- and — , each ap- 

 pearing in four valences. Here K and L are recognized as -|- and — of 

 the lowest valence because they give a weaker sex reaction (grade 2) with 

 each other than do J and M (in C. eugametos f. simplex), or H and N 

 (in C. dresdensjs), or G and O (in C. braunii) . Of the four grades of 

 -|- gametes, G is most diverse from K because it gives the strongest 

 reaction with it; hence G has the highest valence among the -\- gametes. 

 Similarly, O is the — gamete of highest valence, and H and N are the 

 next strongest -|- and — types ( for they react less strongly with K and 

 L than do G and O, while the others do not react at all with them). 

 This leaves J and M intermediate between H and K and between L and 

 N; and this is confirmed by their grades of reaction with G. 



The identification of -|- and — with female and male (in the euga- 

 metos — paupera group of species) is based on differences in morphol- 

 ogy, activity, and function between the gametes in certain species, and 

 on the assumed identity of the sex differences in all the species. In C. 

 coccijera and C. hraun'ii, as set forth on pages 667, 668, the two 

 kinds of gametes differ markedly in size and behavior during copulation : 

 the smaller gamete empties into the larger one. Further, in C. coccijera 

 the large gametes lack flagella and are nonmotile, while the small gametes 

 have flagella and are motile. Moewus therefore holds that the large, 

 nonmotile gametes of C. coccijera are eggs and so female, while the 

 small, motile gametes are comparable to sperm and so are male. If this 

 be admitted, then the large and the small gametes of C. braunii are also 

 female and male, even though both are flagellated, because in combina- 

 tions between the two species copulation occurs only between large and 

 small gametes. On the same grounds, the gametes of isogamous species 

 are female and male, because of the two physiological kinds of gametes 

 in C. eugametos f. typica (types H and N), H will copulate only with 

 the small gametes of C. braunii while N will copulate only with the 

 large ones. Thus the -|- sex has been identified with female and the — 

 with male in C. eugametos f . typica. And, since -|- and — were assumed 

 to be the same in all races and species, female and male must be the same 

 in all races and species. The copulations between female gametes (or 

 between male gametes) of different races must then be consequences of 

 difference of sex valence. 



