102 SEX 



crab so well illustrates. Oftener, however, we 

 find cases where in a female's body normally 

 latent masculine characters are awakened 

 into expression. 



A number of interesting experiments have 

 been made with organisms that are often, 

 but not always, hermaphrodite, such as the 

 grey freshwater polyp, Hydra grisea, and the 

 prothallia (sexual generation) of some ferns. 

 It has been shown that optimum conditions 

 result in a predominance of females, and that 

 groups wholly male can be produced by re- 

 lative starving. What happens in these cases 

 is the inhibition or suppression of one set of 

 sex-organs in favour of another, and although 

 the frequent or normal occurrence of herma- 

 phroditism removes the instances given from 

 the case of ordinary unisexual organisms, we 

 submit that the facts are relevant in showing 

 how closely sex and metabolism are wrapped 

 up together. 



POSSIBLE IMPORTANCE OF THE RELATIVE 

 CONDITION OF THE GERM-CELLS AT FERTILISA- 

 TION. A second theory a favourite one 

 with breeders supposes that the sex of the 

 offspring is settled by the relative condition 

 of the germ-cells at the time of fertilisation. 

 Some say that if the ovum come from a 

 young mother and the sperm from an older 

 father, the offspring will tend to be male. 

 Others say that an ovum fertilised soon after 

 ovulation is likely to develop into a female. 

 Many breeders maintain that the sex of the 

 offspring tends to be that of the more vigorous 

 parent a favourite theory with the fathers 

 of many boys. But a solid foundation on 



