132 THE DESCENT OF MAN. Part I. 



above primary check acts chiefly by restraining mar- 

 riages. The greater death-rate of infants in the poorest 

 classes is also very important; as well as the greater 

 mortality at all ages, and from various diseases, of the 

 inhabitants of crowded and miserable houses. The 

 effects of severe epidemics and wars are soon counter- 

 balanced, and more than counterbalanced, in nations 

 placed under favourable conditions. Emigration also 

 comes in aid as a temporary check, but not to any 

 great extent with the extremely poor classes. 



There is reason to suspect, as Malthus has remarked, 

 that the reproductive power is actually less in barbarous 

 than in civilised races. We know nothing positively on 

 this head, for with savages no census has been taken ; 

 but from the concurrent testimony of missionaries, and 

 of others who have long resided with such people, it 

 appears that their families are usually small, and large 

 ones rare. This may be partly accounted for, as it is 

 believed, by the women suckling their infants for a pro- 

 longed period; but it is highly probable that savages, 

 who often suffer much hardship, and who do not obtain so 

 much nutritious food as civilised men, would be actually 

 less prolific. I have shewn in a former work, 52 that 

 all our domesticated quadrupeds and birds, and all 

 our cultivated plants, are more fertile than the corre- 

 sponding species in a state of nature. It is no valid 

 objection to this conclusion that animals suddenly 

 supplied with an excess of food, or when rendered very 

 fat, and that most plants when suddenly removed from 

 very poor to very rich soil, are rendered more or less 

 sterile. We might, therefore, expect that civilised 

 men, who in one sense are hifrhlv domesticated, would 



52 ' Variation of Animals and Plants under Domestication,' vol. ii. 

 p. 111-113, 163. 



