MECHANICS OF THE MASCULINE AND FEMININE 135 



Our knowledge here, as everywhere, is still fragmentary. Sta- 

 tistical reviews seem to show that in times of stress, war, famine, 

 pestilence, more boys are born than girls. But that is neither 

 here nor there. It sheds no further light on the subject. Mono- 

 sexuality is a distinction of the human species: the sexes are 

 pretty clearly differentiated. In some animals, such as some 

 worms, there is a bisexuality of the individual. There are present 

 the reproductive organs of both sexes, capable of impregnating 

 other individuals as well as of being impregnated. In some of 

 these, even self-impregnation may occur. This is the condition 

 of hermaphroditism. 



But the higher up one goes in the scale of evolution, the greater 

 becomes the distinction between the sexes. Anatomic hermaphro- 

 ditism becomes a rare anomaly. Life appears to have perfected 

 this trick of separate sexes, sex specialization, in short, for the 

 sake of the efficiency which goes with specialization. 



When a germ cell divides, its nuclear material breaks up into 

 segments known as chromosomes. Now it has been found, for 

 example in the case of the common squash bug, anasa tristis, 

 that there are 22 chromosomes in the female, and 21 in the male. 

 In the female two of these are visibly different from the rest, 

 while in the male there is one odd one, the remaining 20 being 

 like the corresponding 20 of the female. Before the germ cell 

 becomes fit to mix with a germ cell of opposite sex, in the process 

 of fertilization, it must lose one half of these. So the number 

 of chromosomes for the species is kept the same or constant. This 

 is the process of maturation. In the process, when the chromo- 

 some number is halved among the females, 11 go into each 

 mature egg. But among the males, the odd chromosome, also 

 known as the X-chromosome, can perforce go only into half of 

 the sperm cells, leaving the others without it. So the sperm are 

 formed in equal numbers of 10 and 11 chromosomes respectively. 



When fertilization occurs, and the sperm cell fuses with the egg, 

 the following may take place: (1) a ten chromosome sperm may 

 unite with the eleven chromosome egg, and produce a twenty-one 

 chromosome individual or (2) an eleven chromosome sperm may 

 unite with an eleven chromosome egg producing a twenty-two 

 chromosome individual. It has been found that the twenty-two 

 chromosome individual invariably develops into a female, and the 

 twenty-one into a male. Therefore, femaleness is a positive qual- 

 ity, dependent upon the action of the X-chromosome, and male- 

 ness an absence of femaleness, due to lack of the extra, odd 



