7 54 



SU3JECT INDEX 



during, ib. ; kidney during, ib. ; heart 

 during, ib. ; urine during, ib, ; respira- 

 tion during, ib. ; brain during, ib. sq. ; 

 production of spermatozoa during, 720, 

 727 ; in horse, 721 



Seps, formation of corpus luteum in, 145 



Seps chdlcides, yolk-sac in, 415 



Serine, 288, 304 



Serotina, 398, 401 ; of mouse, 469 



Serum, composition of ash of, in dog, 595 



Sex-diSerentiation in Bonellia, 692 



Sex-determination, 11^ 201, 296, 331; 

 Chapter XV. ; classification of theories 

 of, 662 ; in frog, 662 sq., 668 ; influence 

 of food on, 662 sqq. ; in Amphibia, 663 ; 

 in lamprey, 664 ; in Lepidoptera larvae, 

 ib. ; in fly larvae, ib. ; in bees,-i6. sqq. ; 

 in termites, 665; in Nematua ventri- 

 cosus, ib. sq. ; in Crustacea, 666 ; 

 effect of fertilisation on, ib. sq. ; in 

 Hymenoptera, 667 ; in saw-flies, i6. ; 

 in Hydatina, ib. ; in Hydatina senta, 

 668 ; in cattle, ib. ; effect of time of 

 fertilisation, ib. sq. ; in man, 668 ; 

 in toad, 669 ; influence of nutrition 

 and environment on, ib. sqq. ; by 

 maturity of ovum, 669 ; in rats, ib. ; 

 in mice, ib. ; in plant-lice, ib. ; by 

 sexual gametes, 671 sq. ; in Talmporia 

 tubulosa, 671 sq. ; by dimorphism of 

 spermatozoa, 672 ; in Anasa iristis, ib. ; 

 in Oalgulus oculatus, 673 ; XY type of, 

 674 ; in DrosopMla, ib. ; in phyl- 

 loxerans, tb. n. ; in Datura, 675 ; 

 WZ type, of, 678 ; in Lepidoptera, 678 ; 

 in birds, ib. ; in Myriapods, ib. ; in 

 Nematodes, ib. ; in spiders, ib. ; in 

 Mammalia, ib. ; in Prcmpits hybridus, 

 679 ; in Simocephalus, 681 ; effect of 

 age of parents on, 683 sq. ; effect of 

 parental vigour on, 684 ; effect of nutri- 

 tion on, 684 sqq. ; in pigeons, 685 sq. 



Sex-linked characteristics, in Drosophila 

 ampelophila, 675 sq. ; in Abraxa 

 grossutariata, 676 ; in Abraxas lacticolor, 

 ib. ; in canaries, 677 ; in fowl, ib. 



Sex-metaboUsm in Inachus, 691 



Sex-ratio, in man, 662 ; in Todas, ib. ; in 

 I^ance, 687 ; in Russia, ib. ; in Sweden, 

 ib. ; in Loudon, ib. 



Sex-reversal, in Crepidula fornicata, 692 ; 

 in Grepiduta plana, ib. ; in Triton 

 alpestris, 693 ; in frog, ib. 



Sexual activity in male, 170 



Sexual attraction in Dacus, 12 



Sexual characters, secondary, 25 



Sexual inversion, 691 



Sexual latency, 688 sqq. 



Sexual organs, biochemistry of. Chapter 

 Vllf . ; relation of thyroid to, 384 



Sexual rest, energy requirements during, 

 519 



Sexual season, definition of, 32 



Sheep, breeding season in, 24 ; dioestrous 

 cycle in, 34 ; oestrous cycle in, 39, 42 



sq. ; practice of flushing, in, 41, 634 

 sq. ; uterine cycle in, 103 ; uterine 

 mucosa in, 105 ; ovulation in, 131 ; 

 formation of corpus luteum in, 14JL sq., 

 146 ; form of spermatozoa in, 169 ; 

 in-breeding in, 218 ; ampulla of Henle 

 in, 240 ; effect of castration in, 323 

 sq. ; ovum of, 404 ; prochorion of, 

 406; yolk-sac in, 415, 420; blasto- 

 cyst of, 421 ; placenta of, 428 agj., 

 449, 509 ; blastodermic vesicle of, 

 430 ; ioetal vilU of, 431 ; histology 

 of placenta of, 435 ; foetal nutrition in, 

 456 ; trophoblast of, 464 ; fixation of 

 blastocyst in, 509 ; Isevulose in foetus 

 oJE, 537 ; blood of, during pregnancy, 

 556 ; uterine contraction in, 562 ; 

 udder of, 586 ; size of fitters in, 623 ; 

 fertility in, J332 sqq., 696 sqq. ; barren- 

 ness in, 633 ; effect of food on fertility 

 in, 634 ; share of ram in fertility of, 

 635 ; inheritance of fertility in, 642 

 sq. ; causes of abortion in, 655 ; foetal 

 atrophy in, 656 ; growth of, 707 

 sqq. ; puberty in, 714 ; menopause in, 

 717 ; longevity in, 723. See also Ovis 

 species 



Shrew, oestrous cycle in, 55 ; formation of 

 corpus luteum in, 139, 145; placenta 

 of, 409, 481 sqq. ; yolk-sac in, 424 ; 

 placenta of, 481 sqq.; blastocyst of, 481; 

 trophoblast of, ib, sq. ; omphaloidean 

 syncytium of, 482 ; oytoblast of, ib. ; 

 plasmodiblast of, 483 ; embryo of, ib. 



Siderophores, 448 



Silkworm, effect of castration in, 325 



Silver-sided, minnow, see Menidia 



Simiidse, placenta of, 408 



SvmocepJialus, parthenogenesis in, 670 ; 

 sex-determination in, 681 



Sinus ensiformis, 425 



Sinus terminaUs, 412 



Siphostoma floridcB, marsupium of, 690 



Sirenia, placenta of, 408 sq., 410, 442 ; 

 position of mammary glands in, 586 



Sinn in pregnancy, 559 



Sloth, position of mammary gland in, 586 



Snake, phenomena associated with breeds 

 ing in, 28 



Snipe, mating habits of, 25 



Sodium, in egg of fowl, '278 ; in foetus of 

 man, 547 ; in milk, 594 ; in ash of pup, 

 595 ; in milk of dog, ib. ; in serum of 

 dog, ib. 



Soma, effect of, on germ-cells, 208 sqq. 



Somatic stalk of yolk-sac, 415 



Somatopleur, 412 ; of bat, 489 



^orex, see Shrew 



Size of offspring in relation to food 

 supply, 522 



Sparrow, breeding season in, 22 ; follic- 

 ular atresia in, 152 sq. 



Sperm agglutination, in Nereis, 186 ; in 

 Arbacia, ib. 



Spermatid, 162 sq. ; in man, 163 



