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as the ' Old World ' is concerned. In what eminent manner the ' far west ' is represented, I have 

 told you at an earlier period. 



"And this leads me to the route which American birds follow to Europe. I do not much 

 lean to the supposition that storms have in any considerable degree to do with such extra tours ; 

 and why Newton and others advance so strongly the Greenland, Iceland, &c. route I cannot 

 comprehend. I fancy they never contemplated the possibility of a bird coming in a direct line 

 from Newfoundland to Ireland — in other words, that a bird might be able to sustain an uninter- 

 rupted flight sufficient to carry it across the Atlantic. My researches have led me to the belief 

 that such is not alone far from being impossible, but that the probability of such a fact, 

 wonderful as it may appear, is borne out by good evidence." 



It is somewhat remarkable that so many American species should have been obtained on 

 this small island ; and I may mention that in Mr. Gatke's unique collection I observed fine 

 examples of Turdus migratorius, Turdus swain soni, Mimus carolinensis, Harporhynchus rufus, 

 Lendroeca virens, and Charadrius virginicus, which species I have not deemed it advisable to 

 include in the European avifauna. 



One subject that is worthy of especial notice is the variation in coloration of plumage in 

 many species ; and it is a difficult matter to decide whether these forms should be treated as 

 distinct species or only as climatic varieties of the same species. Amongst these I may enumerate 

 Phylloscopus swperciliosus and Phylloscopus humei, Phylloscopus viridanus and Phylloscopus 

 nitidus, which differ merely, and but very slightly, in tint of plumage. One observes these 

 differences in tint of plumage more especially on islands. On those which are at some distance 

 from the mainland, where the sun is often obscured, and the atmosphere is dull and heavy, the 

 plumage of the brighter-coloured birds is more sober and dull. Our Greenfinch under the 

 bright skies of Southern Europe and North Africa becomes so richly coloured that it has been 

 described as a distinct species ; and our common Linnet, Linota cannabina, in South-eastern 

 Europe and Asia Minor is very much brighter in tint of colour ; and so richly coloured are 

 specimens from Gilgit that Dr. Scully is inclined to separate specifically the birds obtained there. 

 I was also much struck with the rich and deep coloration of the specimens obtained by him 

 of Carpodacus erythrinus, which are much darker and deeper in tint of coloration than any I 

 have seen. Examples from India are. as a rule, more pink and paler than those from Eastern 

 Europe ; but those obtained by him are darker and much redder than any I have seen from 

 Europe. Another species that varies widely according to the locality where it is procured is 

 Galerita cristata ; and it is only by collecting together a large series from various localities that 

 one can prove that all the various forms are mere varieties, excepting Galerita isabellina, which 

 inhabits the desert portion of North Africa, and is a pale sandy-coloured but constant form 

 of our Crested Lark, and Galerita macrorhyncha, which has become specifically separable 

 from Galerita cristata. In many species which frequent the desert region one finds forms not 

 differing from examples of the same species found in more fertile regions, except in tone of 



