514 LAWS OF MULTIPLICATION. 



— the overtaxing of the nervous system is so apt to prostrate 

 the heart and derange the digestion; that the incapacities 

 caused in these cases, are probably often due more to con- 

 stitutional disturbance than to the direct deduction which 

 excessive action entails. Such instances harmonize with the 

 hypothesis; but how far they yield it positive support we 

 cannot say. 



§ 368. An objection must here be guarded against. It is 

 likely to be urged that since the civilized races are, on the 

 average, larger than many of the uncivilized races ; and since 

 they are also somewhat more complex as well as more active ; 

 they ought, in conformity with the alleged general law, to 

 be less prolific. There is, however, no evidence to prove that 

 they are so : on the whole, they seem rather the reverse. 



The reply is that were all other things equal, these 

 superior varieties of men should have inferior rates of in- 

 crease. But other things are not equal; and it is to the 

 inequality of other things that this apparent anomaly is 

 attributable. Already we have seen how much more fertile 

 domesticated animals are than their wild kindred; and the 

 causes of this greater fertility are also the causes of the 

 greater fertility, relative or absolute, which civilized men 

 exhibit when compared with savages. 



There is the difference in amount of food. Australians, 

 Fuegians, and sundry races that might be named as having 

 low rates of multiplication, are obviously underfed. The 

 sketches of natives contained in the volumes of Livingstone, 

 Baker, and others, yield clear proofs of the extreme depletion 

 common among the uncivilized. In quality as well 



as in quantity, their feeding is bad. Wild fruits, insects, 

 larvse, vermin, &c, which we refuse with disgust, often enter 

 largely into their dietary. Much of this inferior food they 

 eat uncooked; and they have not our elaborate appliances 

 for mechanically-preparing it, and rejecting its useless parts. 

 So that they live on matters of less nutritive value, which 



