14 DAEWINISil STATED BY DARWIN HIMSELF. 



There does not seem to be any great diflBculty in under- 

 standing how an organism, formed by the conjugation 

 of two individuals which represented the two incipient 

 sexes, might have given rise by budding first to a monoe- 

 cious and then to an hermaphrodite form ; and in the 

 case of animals even without budding to an hermaphro- 

 dite form, for the bilateral structure of animals perhaps 

 indicates that they were aboriginally formed by the fusion 

 of two individuals. 



WHY THE SEXES HAVE BEElir EESEPAEATED. 



It is a more difiBcult problem why some 

 plants, and apparently all the higher animals, 

 after becoming hermaphrodites, have since had their sexes 

 reseparated. This separation has been attributed by some 

 naturalists to the advantages which follow from a division 

 of physiological labor. The principle is intelligible when 

 the same organ has to perform at the same time diverse 

 functions ; but it is not obvious why the male and female 

 glands, when placed in different parts of the same com- 

 pound or simple individual, should not perform their 

 functions equally well as when placed in two distinct in- 

 dividuals. In some instances the sexes may have been 

 reseparated for the sake of preventing too frequent self- 

 fertilization ; but this explanation does not seem prob- 

 able, as the same end might have been gained by other 

 and simpler means, for instance, dichogamy. It may be 

 that the production of the male and female reproductive 

 elements and the maturation of the ovules was too great 

 a strain and expenditure of vital force for a single in- 

 dividual to withstand, if endowed with a highly complex 

 organization; and that at the same time there was no 

 need for all the individuals to produce young, and conse- 



