408 



INDEX AND GLOSSARY 



Variety, an incipient species, 147 



Vasc'ular (vasciiltun, a small vessel) 

 bundles, 345, 348 



Vascular plants, 365 



VAUCHERIA (after J. P. E. Vaucher, a 

 Swiss botanist) : Figure, 170 : occur- 

 rence and general characters, 169 : minute 

 structure, 169 : asexual reproduction, 171: 

 sexual reproduction, 172 : nutrition, 175 



Veins of Dogfish, 329 : of leaves, 352 



Vel'um (velum, a veil) of medusa, 241 



Vent, the aperture of the cloaca, 324 



Venter (venter, the belly), of ovary of 

 Moss, 336, and Fern, 358 : of the female 

 sporophyll or of the entire gynoecium of 

 Angiosperms (so-called ovary) 381 



Ventral nerve-cord : Polygordius, 286 : 

 development of, 301 : Crayfish, 319 



Ventricle. See Heart. 



Vermes, the, 308 



Ver'tebral^T^ra, a joint) centra and 

 column, Dogfish, 328 



Vertebrata, the, 309 



Vessels : of plants, spiral and scalariform, 

 348, 349 : of animals, see Blood-vessels. 



Vestige, vestigial (vestigium, a trace), 

 applied to any structure which has be- 

 come atrophied or undergone reduction 

 beyond the limits of usefulness, 118 



Vib'riO (vibro, to vibrate), 86, 88, (Figure) 



ViSC'eral (viscns, an internal organ), ap- 

 plied to the layer of coelomic epithelium, 

 or of peritoneum, covering the intestine 

 and other internal organs, 277 

 Visceral ganglion, Mussel, 323 



Vitelline (vitellus, yolk) membrane, the 



cell-membrane of the ovum, 259 

 Volvox (volvo, to roll), 267, 268, 269. 



(Figure*) 



VORTIOELLA (diminutive of vortex, 

 eddy) : Figure, 127 : occurrence .. 

 general characters, 126 : structure, 126 : 

 asexual reproduction, 131 : conjugation, 

 132 : means of dispersal, 132-136 : ency-<- 

 tadon, spore-formation, development, 

 and metamorphosis, 133 



W 



Waste-products, 33 

 Water of organisation, 5, 29 

 Whorl of leaves, 208 

 Wood. See Xylem. 

 Work and Waste, 14 



Xylem (uAoi/, wood), the inner portion o. 

 vascular bundle, 349 



Yeast, 7 r 



Yeast-plant. See Saccharomyces. 

 YellOW-cells of Radiolaria, 154 

 Yolk-granules or spheres, 68, 235, 



Zoogloe'a (<aov, an animal : -y/Aoi'a, glue), 

 85 



Zooid (a>oc, an animal* etSos, form), a 

 single individual of a compound organism, 

 137, 237 



Zootham'nium (^(aov, an animal : 0t.,xi;o?, 

 a bush): Figures, 134, 138: OCL -rence 

 and general characters, 135 -.dimorphism 

 ofzooids, 135: means of dispersal, 136: 

 characters arid mutual relations of species, 



Zooxanthell'a (fo>oi> an animal : ai'06?, 

 yellow), 154 



Zyg'ospore(c;iryoi>, a yoke : <ntopa, a seed), 

 applied to a resting zygote formed by the 

 conjugation of similar garnet , 166 



ZygOte (vywTos, yoked), the p.oducts of 

 conjugation of two gametes : Hetero- 

 mita, 41 : Vorticella, 133 : Mucor, 165 : 

 Vaucheria, 174 : Spirogyra, 198-200. 



THE END 



RICHARD CLAY AND SONS, LIMITED, LONDON AND BUNUAY. 



