18 SCIENCE PROGKESS: 
cation of a genus into a variety of species. It has been 
further continued, and the same end promoted, by the rami- 
fication of a species into several varieties.” 
The seventh and last section (p. 575) of this part of the 
work treats ‘“‘Of the Relation of Particular Varieties of the 
Human Species to Climates”. 
Prichard evidently thought that adaptation of races to 
climate is especially characteristic of the human species, and 
must be admitted to hold in certain instances whatever be 
thought of his hypothesis that “the varieties in the species 
of animals proceed from a principle in nature, modifying 
the structure and constitution of races, and adapting them 
to the physical circumstances under which these races may 
beweestined (to exist - ~ te considers’ that the seis. 
tribution of the races of men bears ‘‘a certain relation to 
climates,” and gives a broad sketch of the geographical 
arrangement of races in support of this opinion. At the 
conclusion, after inquiring how it is that ‘‘these varieties 
are developed and preserved in connection with particular 
climates and differences of local situation,” he gives the 
following very significant answer : ‘‘ One cause which tends 
to maintain this relation is obvious. Individuals and families, 
and even whole colonies, perish and disappear in climates 
for which they are, by peculiarity of constitution, not 
adapted. Of this fact proofs have been already mentioned.” 
We have here the undoubted recognition of natural selec- 
tion, and it is remarkable that a man of such penetration 
who recognised fully that domestic breeds are due to man’s 
selection, should not have seen in this principle. a larger 
importance and have extended it to the relations of species 
to each other as well as to their physical environment. 
Great as Prichard was he did not appreciate the most 
pressing part of the “struggle for existence”. 
Prichard furthermore considers it probable that there 
are local influences which “‘promote the appearance of 
those varieties which are best suited to them, or tend to 
give rise to their production in the breed”. He freely 
admits that this conclusion conflicts with his contention in 
section ii, that the colour of a race is not permanently 
