42 THE MIGRATIOX OF BRITISH BIRDS 



Rustic Bunting, and the Eagle and Scops' Owls ! Dr. 

 Wallace states that this list " is very interesting when 

 we consider that these countries are separated by the 

 whole extent of the European and Asiatic continents, 

 or by almost exactly one-fourth of the circumference of 

 the globe." Out of the fifty-three species enumerated 

 eleven have no right whatever to be classed as British 

 at all, but are abnormal or nomadic migrants from the 

 far East, from the South, or North ; whilst in the other 

 instances the area of distribution between Britain and 

 Japan is continuous, or intermediate sub-specific forms, 

 due chiefly to climatic variation, constitute an unbroken 

 link between species common to both countries ! Such 

 statements are terribly misleading to the student, shake 

 his confidence in work in which he is not sufficiently 

 expert or has not the requisite special knowledge to test 

 its accuracy, and illustrate very forcibly how absolutely 

 necessary it is that naturalists should thoroughly under- 

 stand not only the rudiments but the higher philosophy 

 of the Geographical Distribution of Life, before they 

 attempt to theorize upon it or endeavour to demonstrate 

 it. Ne sHtor ultra crepidain just as aptly applies to 

 scientists in general, and to Royal Institution lecturers 

 in particular, as to shoe-makers or any other craftsmen. 

 It now becomes necessary to glance briefly at the 

 Canary Islands and the Cape Verds. The former group 

 is situated off the coast of West Africa between the 27th 

 and 29th parallels of latitude, and the nearest of the 

 islands are not much more tiian fifty miles from the 

 continent. They are separated from Africa by a channel 

 more than 830 fathoms in depth, are mountainous, and 

 are entirely volcanic. Dr. Wallace is of the opinion that 



