February 3, 19 16] 



NATURE 



617 



the male birds, in hurrying on, are in any way j 

 conscious of this particular end to be attained. 

 Mr. Howard knows well that the sexual organs \ 

 of these males are beginning to be enlarged before 

 migration, i.e. the sexual impulse lies behind the j 

 whole operation. If the females of these species i 

 are weaker in vitality at the time of migration,^ j 

 this might be enough (as Darwin, I think, ! 

 thought) to account for the earlier arrival of the j 

 males. More convincing is Mr. Howard's oft- i 

 repeated assertion that he has seen nothing in j 

 these territories to support the theory of sexual ^ 

 selection. What seems to happen is this : a male 

 arrives and takes possession of a territory, and 

 sings vigorously, awaiting a female. If another 

 male intrudes, either before or after the appear- 

 ance of the female, fights ensue and the intruder 

 is driven out, but there is no indication that the 

 female ever chooses between two males. The 

 song and the strange antics (of which the book 

 contains many beautiful drawings) are the result 

 of sexual emotion, but are not the result of rivalry 

 with another individual. The object is rather to 

 overcome the coyness of the female — which 

 reminds me of Mr. Crawley's theory of a similar 

 phenomenon among primitive human beings, only 

 to be overcome by a ceremonv, t.e. marriage. 

 This view of the bird's emotional antics leads Mr. 

 Howard to another theory, viz., that the instinct 

 known as " shamming wounded " is only an emo- 

 tional display of the same kind. In this he was 

 in part anticipated by Mr. W. H. Hudson, who, 

 in his " Birds in a Village " (p. 64, cp. " Naturalist 

 in La Plata," chap, xv.), explained the nearly 

 related death-feigning instinct by actual paralysis 

 of the nervous system. More careful observa- 

 tion, combined with physiological knowledge, is 

 needed here. Yet another interesting problem is 

 discussed in connection with the blackcap and 

 marsh warbler, viz., the imitative faculty in song, 

 where the mystery consists in the fact that birds 

 of the year seem to be able to make these imita- 

 tions without having ever heard the songs which 

 they mimic. 



I have perhaps said enough to give some idea 

 of the importance of this contribution to our 

 knowledge of the life of these warblers, and of the 

 urgent need of the embodiment of some of its main 

 conclusions in a cheaper form. I will conclude 

 this notice by congratulating the author on having 

 written the first complete account of the marsh 

 warbler and its life during the breeding season. 

 It is, perhaps, a pity that he should have cum- 

 bered this account by a preliminary twenty pages 

 of somewhat obscure biological discussion, which 

 might have formed an appendix or a chapter by 

 itself; but when he is telling what he has himself j 

 NO. 2414, VOL. 96] 



seen of this charming species, nothing could be 

 better. Only on one or two small points does 

 my experience differ from his. He believes that 

 this bird originally built in reeds like the reed 

 warbler, on no other ground that I can discover 

 but that the nest is sometimes hung in its sup- 

 porting plants after the fashion of that closely 

 allied species. I do not for a moment doubt his 

 statement, but during my long experience of 

 marsh warbler nests, both in England and abroad, 

 I have never seen one that I could not recognise 

 as such at once. One other point I would contest 

 with him. I believe it to be quite impossible that 

 this species should have been freely distributed in 

 England and yet undiscovered up to the middle 

 of the last century ; surely the extraordinary bril- 

 liancy of the song is sufficient proof of this. The 

 nest, too, is by no means hard to find, yet among 

 old collections the only undoubted marsh warbler's 

 ^^% I have ever seen is one found in Somerset 

 some sixty-five years ago, which is now in the 

 possession of the Rev. O. Pickard-Cambridge, of 

 Bloxworth. I am strongly of opinion that the 

 bird has long been, and still is, slowly increasing 

 its range. W Warde Fowler. 



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