PROPORTION OF THE SEXES. ^81 



of the blackbird, he likewise maintained, were bv far the more 

 numerous, whether caught by traps or by netting at night. These 

 statements may apparently be trusted, because this same man said 

 that the sexes are about equal with the lark, the twite {^Linaria 

 montana), and goldfinch. On the other hand, he is certain that with 

 the common linnet, the females preponderate greatly, but unequally, 

 during different years; during some years he has found the females 

 to the males as 4 to 1. It should, however, be borne in mind, 

 that the chief season for catching birds does not begin till September, 

 so that with some species partial migrations may have begun, and 

 the flocks at this period often consist of hens alone. Mr. Salvin 

 paid particular attention to the sexes of the humming-birds 'n Cen- 

 tral America, and he is convinced that with most of the species the 

 males are in excess; thus one year he procured 204 specimens belong- 

 ing to ten species, and these consisted of 166 males and of only S^ 

 females. With two other species the females were in excess; but 

 the proportions apparently vary either during different seasons or in 

 different localities; for on one occasion the males of Campglopterus 

 hemileucurus were to the females as 5 to 2. and on another occasion* 

 in exactly the reversed ratio. As bearing on this latter point, I may 

 add that Mr. Powys found in Corfu and Epirus the sexes of the 

 chaffinch keeping apart, and "the females by far the most numer- 

 ous;" while in Palestine, Mr. Tristram found "the male flocks 

 appearing greatly to exceed "the female in number. "f So again 

 with the Quiscalus major, Mr, G. Taylor:}: says, that in Florida there 

 were " very few females in proportion to the males," while in Hon- 

 duras the proportion was the other way, the species there having the 

 character of a polygamist. 



Fish. With fish the proportional numbers of the sexes can be 

 ascertained only by catching them in the adult or nearly adult state; 

 and there are many difficulties in arriving at any just conclusion. 

 Infertile females might readily be mistaken for males, as Dr. Giin- 

 ther has remarked to me in regard to trout. With some species the 

 males are believed to die soon after fertilizing the ova. With many 

 species the males are of much smaller size than the females, so that 

 a large number of males would escape from the same net by which 

 the females were caught. M. Carbonnier,| who has especially 

 attended to the natural history of the pike {Esox lucius), states that 

 many males, owing to their small size, are devoured by the larger 

 females; and he believes that the males of almost all fish are exposed 

 from this same cause to greater danger than the females. Neverthe- 

 less, in the few cases in which the proportional numbers have been 

 actually observed, the males appear to be largely in excess. Thus 

 Mr. R. Buist, the superintendent of the Stormontfield exi^eriments, 



*" Ibis," vol. ii, p. 260, as quoted in "Gould's Trochilidae," 1861, p. 52. 

 For the foregoing proportions, I am indebted to Mr. Salvin for a table of his 

 results. 



t " Ibis," 1860, p, 137; and 1867, p. 369. 



% " Ibis," 1862. p, 187. 



ILeuckart quotes Bloch (Wagner, " Handworterbucb der Phys.," B. iv, 

 1853, 8. 77.1), that with fish there are twice as many males as females. 



1 Quoted in the " Farmer," March 18, 1869, p. 369. 



