502 RESULTS AND CONCLUSIONS 



complicated facts of nature by the theory of interbreed- 

 ing, and have looked upon the suggestion that hybridisa- 

 tion was anything but an abnormal circumstance as one 

 of the lamest modes of getting out of an ornithological 

 difficulty. The fact is that these pre-Darwinian scientific 

 men have adopted the theory of evolution only theoreti- 

 cally, and have not yet been able to overcome the effects 

 of early education sufficiently to adopt it practically, and 

 to look upon the facts of nature from the new standpoint. 

 The explanation of these Siberian forms of our well- 

 known species of birds, whether they be or be not 

 connected together by intermediate links, must be sought 

 for in Japan and North China. When we get back into 

 a temperate climate again, we find the familiar forms 

 of temperate Europe reappearing, or nearly so. For 

 example, the greater spotted woodpecker of South Europe 

 is almost identical with that of Japan, whilst that of 

 Siberia is white instead of pale-grey on the under parts. 

 The short-eared owl of South Europe is also identical 

 with that of North China, whilst the adult male of the 

 Siberian form is what ornithologists unmeaningly call the 

 "pale phase" of the species. The same remarks apply 

 to the European, Siberian, and Japanese forms of the 

 Ural owl. The nuthatch of China only differs from 

 ours in being a trifle smaller. The more one examines 

 this subject the more evidence one finds of the existence 

 of forms, the extremes of which are very distinct, but 

 which must be considered as only sub-specifically separ- 

 ated, inasmuch as a series of intermediate forms from 

 intervening localities connects them. Many birds, in 

 addition to the typical or temperate form, have an Arctic 

 form, in which the white is highly developed ; a desert 

 form, in which the yellowish-browns are predominant ; 

 and a tropical form in localities where the rainfall is 



