SEXUALITY 



673 



eugametos. Altogether, there are eight diverse sexes designated in the 

 table by the letters G to O. Two of these occur in C. braunii, two in C. 

 dresdensis, six in C paupera, and six in C. eugametos. Their interrela- 

 tions are shown in condensed form in Table 8. G copulates with all 

 others but H, H with all others except G and J, and so on. The breeding 

 relations in this system of eight sexes is in general similar to the rela- 

 tions shown by the six sexes of the first group of races (Table 7) : any 



Table 8: Breeding Relations in Chlamydomonas sp. (cocc/fera?) , 

 C. braunii, C. dresdensis, C. eugametos AND C. paupera"^ 



* -|" — copulation ; — = no copulation. In each species the sexes found are as follows: in both 

 C. sp. and C. braunii, sexes G and O ; in C. dresdensis, sexes H and N ; in both C. eugametos and 

 C. paupera, sexes H, J, K, L, M, and N. In C. eugametos sexes H and N occur in form typica, J 

 and M in form simplex, K and L in both forms subheteroica and synoica. Data from Moewus, 1936, 

 1937b, 1938a ; and Hartmann, 1934. The designations of the sexes in this table differ from those 

 used by Moewus and Hartmann. Not all combinations between the sexes in different varieties and 

 species have been reported (e.g., the sexes in C. sp. were tested only with the sexes of C. braunii ; and 

 C. braunii was tested with all others except C. paupera), but every possible combination of sexes 

 was made with at least one representative of the sexes. 



sex copulates with any other sex in the group except that sometimes 

 copulation will not take place with the sex next above or below it in 

 the table. 



Nature of the sex differences. — In the preceding section the sexes 

 were defined in terms of the sexes with which they copulate. Two cul- 

 tures are of the same sex if they do not copulate with each other and if 

 each does copulate with all the sexes with which the other copulates. Two 

 cultures are of different sex if they copulate with each other, or if one 



