212 MY LIFE [Chap. 



of showing the great importance of the absence of extensive 

 groups from one region that are present in the adjacent 

 region, even though these groups are not peculiar to either. 

 Thus, the fact that both the bear and the deer families are 

 absent from Africa south of the Sahara, though abundant 

 throughout all Asia and North America, marks out the 

 Ethiopian region as distinctly as does the presence of giraffes 

 and hippopotami, which are now peculiar to it. 



But I show that, in mammals, about one-third of the 

 families in the Palaearctic and the Nearctic regions re- 

 spectively are not found in the other ; while in birds, one- 

 third of the families found in the Palaearctic region are not 

 found in the Nearctic, and one-fourth of those in the Nearctic 

 are not found in the Palaearctic region. These facts prove, 

 I maintain, a radical dissimilarity, although, owing to the 

 fact that temperate Europe and Asia are continuous with 

 tropical Africa and Asia, and temperate with tropical 

 America, neither of the regions we are considering have any 

 important families of birds altogether peculiar to them. Any 

 of my readers who are interested in the problems here stated 

 should read the two articles above referred to. 



Other articles were, "A Representative House of Lords," 

 in the Contemporary Review (June), and "A Suggestion to 

 Sabbath-Keepers," in the Nineteenth Century (October), both 

 which articles attracted notice in the Press. I also wrote 

 a paper criticizing the Rev. George Henslow's views as to the 

 origin of irregular flowers, and of spines and prickles, in 

 Natural Science (September), the three articles being in- 

 cluded in my " Studies." I also reviewed James Hutchinson 

 Stirling's " Darwinianism " in Nature (February 8), and Mr. 

 Benjamin Kidd's " Social Evolution " in the same paper 

 (April 12), as well as an anonymous volume, entitled 

 "Nature's Method in the Evolution of Life," by a writer 

 who suggests vague theories, less intelligible even than those 

 of Lucretius, as a substitute for the luminous work of 

 Darwin. 



In the next year (1895) I wrote an important article on 

 " The Method of Organic Evolution " {Fortnightly Review, 



