394 THE ZOOLOGIST. 



only of resident aliens but also of manumitted slaves. As Aristotle 

 says, Cleisthenes legislated with the deliberate purpose of breaking 

 up the phratries and gentes, in order that the various sections of the 

 population might be mixed up as much as possible, and the old 

 tribal associations abolished. The " reform " was probably a recog- 

 nition and extension of a process already begun ; but is it too much 

 to suppose that we have here the effective beginning of a series of 

 genetic changes which in a few generations so greatly altered the 

 character of the people ? Under Pericles the old law was restored 

 (451 B.C.), but losses in the great wars led to further laxity in practice, 

 and though at the end of the fifth century the strict rule was re- 

 enacted that a citizen must be of citizen-birth on both sides, the 

 population by that time may well have become largely mongrelised. 



Let me not be construed as arguing that mixture of races is an 

 evil: far from it. A population like our own, indeed, owes much of 

 its strength to the extreme diversity of its components, for they 

 contribute a corresponding abundance of aptitudes. Everything 

 turns on the nature of the ingredients brought in. and I am con- 

 cerned solely with the observation that these genetic disturbances 

 lead ultimately to great and usually unforeseen changes in the nature 

 of the population. 



Some experiments of this kind are going on at the present time, 

 in the United States, for example, on a very large scale. Our grand- 

 children may live to see the characteristics of the American popula- 

 tion entirely altered by the vast invasion of Italian and other South 

 European elements. We may expect that the Eastern States, and 

 especially New England, whose people still exhibit the fine Puritan 

 qualities with their appropriate limitations, absorbing little of the 

 alien elements, will before long be in feelings and aptitudes very 

 notably differentiated from the rest. In Japan, also, with the 

 abolition of the feudal system and the rise of commercialism, a 

 change in population has begun which may be worthy of the 

 attention of naturalists in that country. Till the revolution the 

 Samurai almost always married within their own class, with the 

 result, as I am informed, that the caste had fairly recognisable 

 features. The changes of 1868 and the consequent impoverishment 

 of the Samurai have brought about a beginning of disintegration 

 which may not improbably have perceptible effects. 



How many genetic vicissitudes has our own peerage undergone ! 

 Into the hard-fighting stock of mediaeval and Plantagenet times have 

 successively been crossed the cunning shrewdness of Tudor states- 

 men and courtiers, the numerous contributions of Charles II. and 

 his concubines, reinforcing peculiar and persistent attributes which 

 popular imagination especially regards as the characteristic of peers, 

 ultimately the heroes- of finance and industrialism. Definitely intel- 

 lectual elements have been sporadically added, with rare exceptions, 

 however, from the ranks of lawyers and politicians. To this 

 aristocracy art, learning, and science have contributed sparse in- 

 gredients, but these mostly chosen for celibacy or childlessness. A re- 

 markable body of men, nevertheless; with an average "horse-power," 



