82 Recently published Ornithological Works. 



written '^a single syllable antagonistic to Darwin^s Theory 

 of Natural Selection/' we are not at all sure tliat those 

 who have read his interesting essay will be able to acquit 

 him of having committed this indiscretion. It is quite certain 

 that Isolation — the prime factor, according to Mr. Dixon — 

 plays a great part in the modification of species ; for without 

 isolation, as Mr. Dixon himself very clearly shows, the mem- 

 bers of a species can breed freely together, and little or no 

 variation will be produced. But surely neither Darwin nor 

 his disciples have ever ignored the force of this element in 

 the variation of species. Isolation, no doubt, plays a most 

 important part in the preservation of differences when they 

 have arisen. Mr. Dixon has not told us how isolation can 

 make differences. Climatic Influence, of which Mr. Dixon 

 speaks in his second chapter, is, in many cases, an impor- 

 tant factor in their production ; but where this does not 

 come into play, as is often the case, we cannot understand 

 how Mr. Dixon proposes to get on without Natural Selection ; 

 and even when climatic influence is manifestly an impelling 

 cause of variation, " Natural Selection " may be a concomi- 

 tant factor. "While thanking him, therefore, for his essay, 

 we still think that he has failed to show that we can get 

 on " without the aid of the Darwinian Hypothesis.'^ 



9. W. Evans on some Scottish Birds. 



[Notes on the Birds of the Island of Eigg. Pr. K. Phys. Soc. Edinb. 

 1885, pp. 430-448. 



Note on the Breeding of the Marsh-Tit (Parus palustris) in Stirling- 

 shire during 1884. Tojn. ctt. pp. 448-451.] 



Lest any of our readers should be so ignorant of Scottish 

 geography as not to know the precise position of Eigg, we 

 may make a concession, and state that it lies about halfway 

 between the island of Rum and that portion of the mainland 

 where Inverness-shire (to which it belongs) marches with 

 Argyll. On Eigg Mr. Evans passed about five days, and 

 from his own observations, largely supplemented by notes from 

 journals kept by Messrs. J. J. Dalgleish, A. C. Stark, A. F. 



