IXDEX 



63' 



U 



Ulna, 50, 502 



Umbilical cord and umbilicus, 

 597, 613, 615 



Umbilical vesicle, 586 



Umbo, 398 



Umbrella of Medusa, 314 



Unicellular, 231 



Uxio, see Mussel 



Urachus, 615 



Urea, 66, 147 



Ureter, 25 ; and see under 

 various types 



Urethra, see Urinogenital canal 



Uric acid, 66 



Urinary bladder, 23, 147, 375, 

 406, 538, 615 



Urinary tubules, see Nephridium 



Urine, 8, 66, 147 



Urinogenital aperture 



canal, 539, 540 

 duct, 194, 603 

 organs, 193, 466, 



537 



organs, develop- 

 ment of, 600 



Urodeles, 219 



Uropod, 364 



Urostyle, 35, 39 



Uterine crypts, 611 



Uterine tube, 540 



Uterus, 540 



masculinus, 538 



Utriculus, 187 



Vacuole : contractile, 232, 243, 

 254, 265, 269 ; food-, 233, 266, 



A-" 7 " 



\ agina, 540 



Valve : of Vieussens, 529, 531 



(Figs.) ; spiral, 445, 515 ; ilec- 



colic, 515 

 Valves: of heart, 88, 376, 521, 



523 ; of shell, 396 ; of veins, 



89 

 Variation, 216, 225, 292, 483 



Variety, 225 



Vascular system, see Blood- 

 vessels, Arteries, Veins 



Vas deferens, see Spermiduct, 

 Wolffian duct 



Vasa efferentia, see efferent ducts 



Veins : Frog, 19, 82 ; Cravfish. 

 377 ; Mussel, 40 S ; Z 

 454 ; Rabbit, 525 ; embryo 

 Vertebrate, 599, 600 



Veliger. 411 



Velum : of Medusa, 315 ; of 

 Lancelet, 424 



Velum palati, 507 



Vena cava, see Veins 



Vent, see Anus 



Ventral, 6 



Ventricle, see Heart 



Ventricles of brain, 157, 159, 424 

 459, 5^9, 53 i, 590 



Vermiform appendix, 515 



Vertebra and vertebral column, 



16, 35- 36, 439, 497, 604 

 Vertebrarterial canal, see Canal 

 Vertebrata, 220 ; general char- 

 acters of, 418 

 Vessels, see Blood-vessels 

 Vestibule, see Urinogenital canal 

 Vestige, vestigial, 159, 364, 521, 



550 



Vibrissae, 486 

 Villi : of intestine, 515 ; of 



chorion, 611 



Viscera, abdominal, 20, 444, 512 

 Visceral arches and clefts, 438, 

 448 ; and see Branchial aper- 

 tures 



Visceral ganglion, 408 

 Visceral layer of peritoneum, 27, 



33i 



Visceral mass, 399 

 Vitelline membrane, 565, 609 

 Vitelline vessels, 599 

 Vitreous body of compound eye, 



380 

 Vitreous chamber and humour, 



183 



\ocal cords, 144, 517 

 Vocal sacs, 218 

 Vomero-nasal organ, 534 



