INDEX 



967 



Skin of Tunicate, 500. 



— of Vertebrates, 532. 

 Skin-gills of starfish, 296. 

 Skull, 532. 



— development of Vertebrata, 534. 

 Skull of Craniata, 532. 



— of Crocodilia, 710, 710, 7", 714. 



— of frog, 654, 654. 



— of haddock, 619. 



— of lizard, 695, 696. 



— of Mammals, 778, 781. 



— of pigeon, 740. 



— of rabbit, 789, 789, 790, 791. 



— of skate, 592, 592, 593, 



— of snakes, 705, 706, 707. 

 Skunk, 873. 



Sleeping-sickness parasite, 147, 410. 

 Sloth animalcules, 426. 



Sloths, 844. 

 Slough of snake, 703. 

 Slow-worm, 702, 702. 

 Slug, 8, 474, 476. 

 Smynthurus, 384, 407. 

 Snail [see Helix), 8, 436. 



— dissection of, 442. 



— laving eggs, 444. 



— Roman, 436. 

 Snakes, 703. 

 Snake's head, 705. 

 Social life of bee, 377. 



of insects, 404. 



of Mammals, 829. 



Solaster, 292, 298. 

 Solen, 481. 



Solenia, 195. 



Solenocytes, 267. 



Solenogastres, 478. 



Solenomya, 466, 468, 480. 



Solenostoma, 629. 



Solpuga, 417. 



Solpugidce or Solifugae, 417. 



Somatic cells, 88. 



Song of birds, 758. 



Sorex, 876. 



Sounds produced by insects, 389. 



Spadella, 280. 



Spatangus, 305. 



Specialisation in Crustaceans, 354, 353. 



Species, 14. 



Specific characters, 15. 



— differences, 16. 

 Sperm whale, 487, 864. 

 Spermatic cord, 811. 

 Spermothec.TD, 254. 

 Spermatogonium, 68. 

 Spermatophores, 254. 

 Spermatozoa, 63, f<S. 



— forms of, 69. 



— method of entrance of. into egg-cell, 



73, 74- 

 Spermatozoon, diagram of, 68. 

 Sphaeridia, 302. 

 Spha&rophrya, 135. 

 Sphaerozoum, 133. 

 Sphaerularia, 239, 240. 

 Sphargidae, 689. 



Sphenodon, 4, 541, 684, 685, 697. 



— pineal eye in embryo of, 541. 

 Sphenotic, 619. 



Spicules of Alcyonaria, 200. 



— of Holothurians, 306, 306. 



— (of sponge), 158. 

 Spiculum amoris, 445. 

 Spider, 10. 



— dimorphism in, 418. 



— Monkeys, 885. 

 Spiders, 9, 4i7- 



— classification of, 422. 

 Spinal cord, 539. 543, 546. 



— ganglia, 547. 

 nerves, 545, 547- 



Spinnerets, 418, 420. 

 Spinning by Spiders, 421. 



— glands of Insects, 391. 



of Spiders, 420. 



Spio, 498- 



Spiracles of bee, 379. 



— of skate, 554, 602. 

 Spiracular cartilage, 554, 602. 

 Spiral valve of skate, 601, 601. 

 Spirochaete, 150. 



Spirula, 485, 486, 487, 488. 

 Spirulirostra, 488. 

 Splanchnoccel, 522. 

 Spleen, 36. 



— of frog, 667. 



— of pigeon, 752. 



— of rabbit, 803. 



— of skate, 604. 

 Splenial, 534- 



Sponge, canal system of, 156, 



— colony, 154. 



— development of a, 161. 



— early fixed stage of, 163. 



— section ot, 155. 



— simple, 154. 



— spicules, 155, 158. 



— structure, diagram of, 157. 

 Sponges, 12, 66, 153. 



— and Coelentera, 12. 



— classification of, 163. 



— ecology of, 164. 



— embryology of, 163. 



— history of, 164. 



— zoological position of, 165. 

 Spongilla, 164. 

 Spongillidae, 13, 160. 

 Spongioblasts, 158. 

 Sporocyst, 220. 

 Sporogony, 126. 

 Sporozoa, 14, no, 135. 

 Sporozoite, 126. 

 Spring-tails, 384, 407. 

 Squaloraja, 635. 



Squalus, 634. 

 Squamosal, 534. 

 Squid, 458. 

 Squilla, 352. 

 Squirrels, 867. 

 Stagonolepis, 717. 

 Stapes of ear, 550, 793. 

 Starch, digestion of, 30, 31 



