V 

 HUMAN FECUNDITY 



1. As a preliminary to the separate inquiries into the two 

 aspects of the problem, it is necessary briefly to consider the 

 question of human fecundity. 



We may ask, in the first place, whether, taking a broad view of 

 human history, there is any reason to believe that human fecundity 

 has changed since the epoch of the pre-human ancestor, and, if so, 

 whether it has increased or diminished. Secondly, there are 

 a number of habits and customs which have been practised in 

 different degrees at different times, such as prolonged lactation, 

 polygamy, and so on, and we may also ask what bearing, if any, 

 such habits and customs have upon fecundity. 



There is much connected with the subject which is difficult and 

 obscure. It is, in particular, often difficult to ascertain whether 

 any differences in fecundity, as may be found to exist, are of the 

 nature of racial or of environmental differences. Into such points, 

 however, we need not go. We are concerned only with the 

 question as to whether there are differences in fecundity, and we 

 may confine our attention to a notice of any broad differences 

 which do exist and to the question whether certain habits and 

 customs widely practised at one time or another and supposed to 

 bear upon fecundity do or do not have the influence attributed to 

 them. We may begin with the first question set out above. 

 In order to obtain an answer to this question we have to rely upon 

 evidence derived from various sources, partly from primitive 

 races, which we assume in general to exhibit conditions prevalent 

 among prehistoric races, and partly from evidence derived from 

 a study of the mammalian species which have been subject to 

 changes comparable with those to which man has in the course of 

 his history been subject. 



2. From what has been said regarding the nature of reproduction 

 in Chapter II, it follows that it is the female rather than the male 

 that we have to consider. The male gametes vastly outnumber 

 the female, and, generally speaking, the male is always readj^ for 



