BRITISH BIRDS. 119 



Darwin says (' Descent of Man,' vol. ii. p. 180) these are " cases in which 

 diseased or old females assume masculine characters, or those in which per- 

 fectly fertile females, whilst young, acquire, through variation or some 

 unknown cause, the characters of the male. [A^ofe] Mr. Blyth has recorded 

 (translation of Cuvier's ' Regne Animal,' p. 158) various instances with 

 Lanius, Ruticilla, Linaria, and Anas. Audubon has also recorded a similar 

 case (' Ornith. Biog.' vol. v. p. 159) with Tyranga astiva." These and the 

 normal course, in ultimately becoming like the male, "have so much in 

 common, that they depend, according to the hypothesis of pangenesis, on 

 gemmules derived from each part of the male being present, though latent, 

 in the female, their development following on some slight change in the 

 elective affinities of her constituent tissues " (vol. i. p. 291). " The beautiful 

 green speculum on the wings is common to both sexes, though duller and 

 somewhat smaller in the female ; and it is developed early in life, while 

 the curled tail-feathers and other ornaments peculiar to the male are deve- 

 loped later." 



An experienced keeper has assured the author that he has observed, 

 among Pheasants, young females assuming the plumage of the male shortly 

 after leaving the hen-coops, i. e. in a very early stage. 



It is strange that captivity should make the difference of turning a 

 species from a monogamous one into a polygamous ; yet such is the case 

 with Ducks. 



Pishey Thompson, in his ' History of Boston ' (p. 676), says : — " A good 

 account of these decoys in the East Fen is given in Oldfield's ' History of 

 Wainfleet.' In one season, a few years previous to the inclosure of the Fens, 

 ten decoys, five of which were in the parish of Friskney, furnished 31,200 

 Ducks, Widgeon, and Teal for the London market. Oldfield's ' Wainfleet ' 

 (p. 180, and Appendix p. 2) mentions that ' in these times a flock of Wild 

 Ducks has been observed passing along from the north and north-east into 

 the East Fen, in a continuous stream, for eight hours together.' " 



Fuller says : — " Lincolnshire may be called the aviary of England for the 



