: LAWS OF MULTIPLICATION. 



867. Evidence of the converse truth, that relative in 

 crease of expenditure, leaving a diminished surplus, reduces 

 the degree of fertility, is not wanting. Some of it has been 

 set down for the sake of antithesis in the foregoing section. 

 Here may be grouped a few facts of a more special kind 

 having the same implication. 



To prove that much bodily labour renders women less 

 prolific, requires more evidence than is obtainable. Some evi- 

 dence, however, may be set down. De Boismont in France and 

 Dr. Szukits in Austria, have shown by extensive statistical 

 comparisons, that the reproductive age is reached a year 

 later by women of the labouring class than by middle-class 

 women ; and while ascribing this delay in part to inferior 



natural power to increase in any species what it may, the plethoric state 

 invariably checks it. and the deplethoric state invariably develops it ; and this 

 happens in the exact ratio of the intensity and completeness of each state, 

 until each state be carried so far as to bring about the actual death of the 

 animal or plant itself." 



I have space here only to indicate the misinterpretations on which Mr. 

 Doubleday has based his argument. 



In the first place, he has confounded normal plethora with what I have, in 

 355, distinguished as abnormal plethora. The cases of infertility accom- 

 panying fatness, which he cites in proof that over-feeding checks increase, are 

 not cases of high nutrition properly so called ; but cases of such defective 

 absorption or assimilation as constitutes low nutrition. In Chap. IX, abun- 

 dant proof was given that a truly plethoric state is an unusually fertile state. 

 It may be added that much of the evidence by which Mr. Doubleday seeks to 

 show that among men, highly-fed classes are infertile classes, may be out- 

 balanced by counter-evidence. Many years ago Mr. Lewes pointed this out : 

 extracting from a book on the peerage, the names of 16 peers who had, at that 

 time, 186 children ; giving an average of 11 '6 in a family. 



Mr. Doubleday insists much on the support given to his theory by the 

 barrenness of very luxuriant plants, and the fruitfulness produced in plants 

 by depletion. Had he been aware that the change from barrenness to fruit- 

 fulness in plants, is a change from agamogenesis to gamogenesis had it been as 

 well known at the time when he wrote as it is now, that a tree which goes on 

 putting out sexless shoots, is so producing new individuals ; and that when it 

 begins to bear fruit, it simply begins to produce r ew individuals after another 

 manner he would have perceived that facts of this class do not tell in bit 

 avour. 



In the law which Mr. Doubleday alleges, he sees a guarantee for the main 



