BIRGDS. 



INDEX. 



BLY f H. 



627 



frequency of white plumage in, 

 4-93 ; vocal courtship of, 567 ; 

 naked skin of the head and nock in, 

 601. 



Birgus latro, habits of, 270. 



Birkbeck, Mr., on the finding of new 

 mates by golden eagles, 408. 



Birthplace of man, 155. 



Births, numerical proportions of the 

 sexes in, in animals and man, 215, 

 216; male and female, numerical 

 proportion of, in England, 242. 



Bischoff, Prof, on the agreement be- 

 tween the brains of man and of the 

 orang, 6 ; figure of the embryo of 

 the dog, 10 ; on the convolutions 

 of the brain in the human foetus, 

 11 ; on the difference between the 

 skulls of man and the quadrumana, 

 149 ; resemblance between the ape's 

 and man's, 200. 



Bishop, J., on the vocal organs of 

 frogs, 350 ; on the vocal organs of 

 corvine birds, 370; on the trachea 

 of the Merganser, 374. 



Bison, American, co-operation of, 101; 

 mane of the male, 521. 



Bitterns, dwarf, coloration of the 

 sexes of, 461. 



Biziura lobata, musky odour of the 

 male, 359 ; large size of male, 362. 



Blackbird, sexual differences in the, 

 219; proportion of the sexes in 

 the, 248 ; acquisition of a song by, 

 370 ; colour of the beak in the 

 sexes of the, 383, 491 ; pairing 

 with a thrush, 414 ; colours and 

 nidification of the, 455 ; young of 

 the, 487 ; sexual difference in colo- 

 ration of the, 491. 



Black-buck, Indian, sexual difference 

 in the colour of the, 535. 



Blackcap, arrival of the male, before 

 the female, 212; young of the, 

 487. 



Black-cock, polygamous, 219; pro- 

 portion o( the sexes in the, 248 ; 

 pugnacit) and love-dance of the, 

 363 ; call of the, 375 ; moulting of 

 the, 392 ; duration of the court- 

 ship <>f the, 405 ; and pheasant, 

 hybrids of, 414 ; sexual difference 

 in coloration of the, 491 ; crimson 

 eye-cere of the, 491. 



Blacklock, Dr., on music, 572. 



Black-grouse, characters of youngs 

 465, 471. 



Blackwall, J., on the speaking of the 

 magpie, 90 ; on the desertion of 

 their young by swallows, 108 ; on 

 the superior activity of male spiders, 

 221 ; on the proportion of the 

 sexes in spiders, 254; on sexual 

 variation of coloui in spiders, 272; 

 on male spiders, 272. 



Bladder-nose Seal, hood of the, 528. 



Blaine, on the affections of dogs, 

 523. 



Blair, Dr., on the relative liability of 

 Europeans to yellow fever, 194. 



Blake, C. C, on the jaw from La 

 Naulette, 40. 



Blakiston, Capt., on the American 

 snipe, 377 ; on the dances of Tetrao 

 phasianellus, 381. 



Blasius, Dr., on the species of Euro- 

 pean birds, 422. 



Bledius taurus, hornlike processes of 

 male, 299. 



Bleeding, tendency to profuse, 237. 



Blenkiron, Mr., on sexual preference 

 in horses, 524. 



Blennies, crest developed on the head 

 of male, during the breeding sea- 

 son, 338. 



Bletlnsa multipunctata, stridulation 

 of, 302. 



Bloch, on the proportions of the sexes 

 in fishes, 249. 



Blood, arterial, red colour of, 261. 



pheasant, number of spurs in, 



364. 



Bluebreast, red-throated, sexual dif- 

 ferences of the, 472. 



Blumenbach, on Man, 28 ; on the 

 large size of the nasal cavities in 

 American aborigines, 34; on the 

 position of man, 149 ; on the num- 

 ber of species of man, 174. 



Blyth, E., on the structure of the 

 hand in" the species of Ihjlohates, 

 51 ; observations on Indian crows, 

 102; on the development of the 

 horns in the Koodoo and Eland an- 

 telopes, 234; on the pugnacity of the 

 males of Gallinula cristata, 360 ; on 

 the presence of spurs in the female 

 Euplocamus er/jthrophthalmus, 364 ; 

 on the pugnacity of the amadavat, 

 366 ; on the spoonbill, 374; on th« 



