SMALLNESS A CORRELATION 243 



immunity from it is the final explanation of the tropical 

 pygmy race. In the United States black pigs are able to 

 eat, without harm, a common marsh herb, the " Red- root " 

 Lachnanthes tinctoria, which kills other pigs. Hence a 

 black race is established, not because it is black, but be- 

 cause, in it, blackness is " the outward and visible sign of 

 an inward and chemical grace " that is to say, of a physio- 

 logical or chemical power of resistance to, and immunity 

 from, the poison of an otherwise nutritious plant. Such 

 " correlations " were described by Darwin, and are of 

 extreme importance and interest far more so than is, at 

 present, recognised by naturalists. I am inclined to the 

 supposition that the obvious outward signs, the round head, 

 bombous forehead, furry skin, and diminutive size of the 

 pygmies are the outcome of an inward physiological con- 

 dition peculiar to them, which has enabled them to resist 

 disease or to eat certain kinds of food, or possibly to 

 develop great mental acuteness, and so has led to the 

 establishment of these peculiar small people as a race, 

 without their smallness itself having anything to do with 

 their selection and preservation. In that case smallness 

 would be a " by-product," a " correlated " character, not 

 the " effective life-saving " character. 



