4 o8 



INDEX AND GLOSSARY 



Variety, an incipient species, 147 

 Vasc'ular (vascitlum, a small vessel) 



bundles, 345, 34 8 



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 (Center, the belly), of ovary of 

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

 sporophyll or of the entire gyncecium of 

 Angiosperms (so-called ovary) 381 



Ventral nerve-cord : Polygordius, 286 : 

 development of, 301 : Crayfish, 319 



Ventricle. See Heart. 



Vermes, the, 308 



Ver'tebral(r'tv-^ra, a joint) centra and 

 column, Dogfish, 328 



Vertebrata, the, 309 



Vessels : of plants, spiral and scalarifonn, 

 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 



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



ViSC'eral (vise us, an internal organ), ap- 

 plied to the layer of ccelomic 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-^) 



VORTICELLA (diminutive of vortex, an 

 eddy) : P^igure, 127 : occurrence and 

 general characters, 126 : structure, 126 : 

 asexual reproduction, 131 : .conjugation, 

 132 : means of dispersal, 132-136 : encys- 

 taiion, spore- formation, development, 

 and metamorphosis, 133 



W 



Waste-products, 33 

 Water of organization, 5, 29 

 Whorl of leaves, 208 

 Wood. See Xylem. 

 Work and Waste, 14 



X 



Xylem (uAov, wood), the inner portion o. 

 vascular bundle, 349 



Yeast, 71 



Yeast-plant. See Saccharomyces. 

 Yellow-cells of Radiolaria, 154 

 Yolk-granules or spheres, 68, 235, 258 



Zooglce'a (c,"woi>, an animal : -yAot'a, glue), 



8 5 

 Zooid ((ooi', an animal: eifios, form), a 



single individual of a compound organism, 

 137, 237 



Zootham'nium (Cfaov, an animal : fla/u^os, 

 a bush) : Figures, 134, 138 : occurrence 

 and general characters, 135 '.dimorphism 

 ofzooids, 135 : means of dispersal, 136: 

 characters and mutual relations of species, 



I35-I39 



Zooxanthell'a (giaov an animal : ai/06s, 

 yellow), 154 



Zyg'ospore (vyov, a yoke : crnopa., a seed), 

 applied to a resting zygote formed by the 

 conjugation of similar gametes, 166 



ZygOte (uya>Tos, yoked), the products 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 I5UXI.JAV. 



