758 



SUBJECT INDEX 



Vesperugo, formation of corpus luteum in, 

 142, 145 ; retention of ovum in follicle 

 of, 151 



Vesperugo noctula, see Bat 



Vicia, chromosomes of, 206 



Villi, structure and function of, 396 sqq. ; 

 core of, 398 



Virgin, mammary tissue of, 617 ; explana- 

 tion of lactation by, ib. 



Vitab'ty of gametes, 220 



Vital staining, of placenta, 465 sq. ; 

 with trypan blue, ib. ; in rabbit, ib. ; 

 with pyrrol blue, 466 ; in mouse, ib. ; 

 in guinea-pig, ib. ; in rat, ib. ; in cat, 

 ib. ; with Indian ink, ib. 



Vitamins, 529 sq. 



Vitellin, 281 sq., 286, 293 ; composition 

 of, 288 



Vitelline membrane, 184 



Vitellolutein in eggs of M aja squinado, 294 



Vitellorubin in egg of Maja squinado, 294 



Vocal cords, growth of, 713 



Vole, see Arvicola glareolus 



" Vollplacenta," 409 



Vulva, 74 ; innervation of, 560 



W 



Walrus, oastrous cycle in, 45, 54 ; period 



of gestation in, 45, 55 ; lactation period 



in, 55 



Wapiti deer, oastrous cycle in, 45 

 Water-buck, cestrous cycle in, 45 

 Water shrew, cestrous cycle in, 55 

 Water-soluble vitamin B, experimental 



importance of, 529 sq. 

 Weasel, oestrous cycle in, 53 sq. 

 Weather, influence of, on milk, 596 

 " Wellenbewung " hypothesis, 61 sq. 

 Whale, periodicity of breeding in, 29 ; 



oestrous cycle in, 47 ; breeding season 



in, ib. sq. 



Whey albumen in milk, 594 

 White of egg, composition ' of, 277 aq. : 



glucoprotein in, 287 ; ovamucoid in, 



ib. ; ovalbumen in, ib. ; conalbumen 



in, ib. ; " Tata-eggwhite," ib. 

 WiM cat, oestrous cycle in, 52 ; period of 



gestation in, ib. ; breeding season in, 



ib. 



Wild-duck, fertility in, 628 

 " Witch's milk," 595, 615 

 Wolf, breeding season in, 4 ; cestrous 



cycle in, 50 ; period of gestation in, ib. 

 Wolffian body, 114 

 Woodchuck, interstitial cells in testis of, 



163 ; testes of, 331 

 " Work of development," 285 

 Wrasse, see Ctenolabrus 

 WZ type of sex-determination, 678 



Xanthine, 307 



Xanthophyll, 281 



X-chromosome in Lygceus bicrucis, 673 



" Xenia," 208 



Xenia hicksoni, breeding season in, 8 



Xenopus, breeding season in, 19 sq. 



Xenopus Icevis, breeding season in, 19 



X-rays, effect of, on germ - cells, 209 ; 



sterility due to, 645 *q. 

 XY type of sex-determination, 674 



Yak, oestrous cycle in, 45. See also Bibos 

 grunnicus 



Y-chromosome in Lygceus bicrucis, 673 



Yew, abortion caused by, 652 



Yohimbine as cure for impotence, 638 ; 

 effect of, on genital organs, 638 sq. 



Yolk of egg, composition of, 277 sq. ; 

 colour of, 283 ; palmitic acid in, ib. ; 

 oleic acid in, ib. ; stearic acid in, ib. ; 

 lecithin in, ib. ; lutein in, ib. 



Yolk-sac, Chapter X., Part 3 ; origin 

 of, 411 ; of Sauropsida, ib. ; somatic 

 stalk of, 415 ; of Lacertilia, ib. ; in 

 sheep, ib. ; in Seps chalcides, ib. ; in 

 man, ib. ; nutritive importance of, 

 415 sqq. ; in opossum, 415 ; in rabbit, 

 415,422; of Marsupialia, 416; nutri- 

 tive importance of, in Ungulata, 420 ; 

 in horse, ib. in cow, ib. ; in pig, ib. ; 

 in sheep, ib. ; in Carnivora, ib. ; in 

 dog, 421 ; in elephant, ib. ; in Probos- 

 cidea, ib. ; in HyraA, ib. ; in Rodentia, 

 ib. sqq. ; in mouse, 422 sq. ; in rat, 

 422 ; in Acomys caharinus, 423 ; 

 in hedgehog, 424 ; in shrew, ib. ; in 

 Insectivora, ib. sq. ; in mole, ib. ; 

 in Tupaia javanica, ib. ; in bat, 425 ; 

 connecting stalk of, ib. ; in monkey, ib. ; 

 in Primates, ib. sq. 491 ; in man. ib. 



Yolk-spherules, 291 



Yolk-villi, 424 



Zebra, sterility of hybrid, with horse, 642 



Zebu, see Bos indicus 



" Zellsaiilen," 396 ; of man, 500 sq. 



" Zenker's crystals," 299 



Zoarces, formation of corpus luteum in, 



145 

 Zona pellucida, 121, 404, 405 sq. ; of 



hedgehog, 476 



Zoua radiata, 121. See also Corona radiata 

 Zonary placenta, 408, 442 

 Zonary villi of ovum, 445 



