Extracts from Mr. Bentham’s Address, 329 
we may take, for instance, those races which are regarded by 
ides, &e. 
We shall find in each some one form, which we call typical, 
generally prevalent over the greater part of the area of the race, 
whilst others, more or less aberrant, are more or less restricted 
varieties and subspecies are being formed, but have not yet 
obtained sufficient advantages to prevent their being kept in 
check by their intercommunication (and, probably, cross-breed- 
ing) with their more robust type. The British Batologist or 
Rhodologist transported to the south of France or to Hungary 
will still find one, or perhaps two or three forms of Bramble 
and Dog-rose with which he is familiar; but if he wishes to 
discriminate the thirty or forty varieties or subspecies upon 
which he had spent so much labor and acuteness at home, he 
must recommence with a series of forms and combinations of 
e 
medium of that one which is still common to both. When 
that shall have expired, the distinct species may be considered 
established. A still further advance in specific change is exem- 
Am. Jour. Sci.—Szconp Serres, Vor. L, No 150.—Nov., 1870. 
21 
