298 THE rniNCIPLES OF [Part II. 



On tlio other haml, he is certain tliat witli the common linnet, tlio 

 females preponderate greatly, but unequally during different years; 

 during some years he has found the females to the males as four 

 to one. It should, however, be borne in mind, that the chief sea- 

 son for catching birds docs not begin till September, so that ■with 

 some species partial migrations may have begiin, and the flocks 

 at this period often consist of hens alone. Mr. Salvin paid par- 

 ticular attention to the sexes of the humming-birds in Central 

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

 males ai'o in excess; thus, one year ho procured 204 specimens 

 belonging to ten species, and these consisted of 1G6 males and of 

 38 females. "With two other species the females were in excess : 

 but the proportions apparently vary cither during different sea- 

 sons or in different localities; for on one occasion the males of 

 Campyloptcrus Tiemileucurus were to the females as five to two, 

 and on another occasion " in exactly the reversed ratio. As bear- 

 ing on this latter point, I may add that Mr. Powys found in Corfu 

 and Epirus the sexes of the cbaffmch keeping apart, and " the fe- 

 males by far the most numerous;" Avhile in Palestine Mr. Tris- 

 tram found " the male flocks appearing greatly to exceed the fe- 

 male in number." *' 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 llonduras the proportion was 

 the other way, the species there having the character of a i)0- 

 lygamist. 



Fisn. 



"With fish the proportional numbers of the sexes can be ascer- 

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

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

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

 ther has remai'kcd to me in regard to trout. "With some species 



•"8 ' Ibis,' vol ii. p. 260, as quoted in Gould's ' Trochilidiv,' 18C1, p. 52. 

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

 his results. 



" 'Ibis,' 1800, p. 137; and 18C7, p. S09 



"iO'Ibis,' 18G2, p. 187. 



*' Lcuckart quotes Bloch (Wagner, 'Ilandwurtctbuch dor ri.ys.' B. 

 iv. 1853, s. 775), that with fish there arc twice as many males as females. 



