Nature of Sexual Diversity 



129 



Figure 38. Chilodon. Two individuals placed side by side, showing 

 that the mouths, lying at the left side, will not come in contact in 

 conjugation without some alteration of position. Based on a figure 

 by Enriques, 1908. 



Figure 39. Conjugation of Chilodon. The mouth of the left-hand 

 individual has moved over to the right, to meet that of the right-hand 

 individual. After Enriques, 1908 (but reversed in position). 



comes bent, in such a way as to shorten the animal, so that 

 when the two members of a pair are measured, the left 

 member is shorter than the right-hand one. The result of 

 all this is that the two mates have become diverse. Enriques 

 holds this to be the first stage in the production of sex differ- 

 ences; that the right-hand individual corresponds to a fe- 

 male, the left-hand one to a male. He believes that in other 

 species the difference thus produced in the mating process 



