408 



INDEX AND GLOSSARY 



sends off a number of secondary axes 



from its distal end, 136 

 Unicell'ular, formed of a single cell, 61 ; 



connection of uni- with multi-cellular 



organisms, 260-265 

 Ureter (ovprjnjp, the Greek name), the 



duct of the kidney, 326 



VORTICELLA (diminutive of vortex, an 

 eddy) : Figure, 125 : occurrence and 

 general characters, 124 : structure, 126 : 

 asexual reproduction, 129 : conjugation, 

 130: means of dispersal, 130-134: encys- 

 tation, spore-formation, development, 

 and metamorphosis, 131 



Vac'uole (vacuus, empty), contractile, n, 

 109: non-contractile, 70 



Variability, 145 



Variation, individual, 138, 145 



Variety, an incipient species, 145 



Vasc'ular (vasculum, a small vessel) 

 bundles, 341, 344 



Vascular plants, 361 



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

 Swiss botanist) : Figure, 168 : occur- 

 rence and general characters, 167: minute 

 structure, 167 : asexual reproduction, 169: 

 sexual reproduction, 170 : nutrition, 173 



Veins of Dogfish, 325 : of leaves, 348 



Vel'um (velum, a veil) of medusa, 240 



Vent, the aperture of the cloaca, 320 



Venter (venter, the belly), of ovary o. 

 Moss, 332, and Fern, 354 : of the female 

 sporophyll or of the entire gynoecium of 

 Angiosperms (so-called ovary), 377 



Ventral nerve-cord : Polygordius, 282 : 

 development of, 297 : Crayfish, 315 



Ventricle. See Heart. 



Venues, the, 304 



Ver'tebral (vertebra, a joint) centra and 

 column, Dogfish, 324 



Vertebrata, the, 305 



Vessels : of plants, spiral and scalariform, 

 344, 347 : of animals, see Blood-vessels. 



Vestige, vestigial (vestigium, a trace), 

 applied to any structure which has become 

 atrophied or undergone reduction beyond 

 the limits of usefulness, 115 



Vib'rio (vibro, to vibrate), 85, (Figure) 87 



Visc'eral (viscits, an internal organ), ap- 

 plied to the layer of ccelomic epithelium, 

 or of petitoneum, covering the intestine 

 and other internal organs, 273 



Visceral ganglion, Mussel, 319 



Vitelline (vitellus, yolk) membrane, the 

 cell-membrane of the ovum, 255 



VolVQX (volvo, to roll), 263 (Figure) 



W 



Waste-products, 33 



Water of organization, 5, 29 



Whorl of leaves, 206 

 Wood. See Xylem. 

 Work and Waste, 14 



X 



Xylem (u/\oi', wood), the inner portion ot 

 vascular bundle, 345 



Yeast, 70 



Yeast-plant. See Saccharomyces. 

 YellOW-cells of Radiolaria, 152 

 Yolk-granules or spheres, 68, 232, 254 



Zoogl03'a (<aov, an animal : y\oia, glue). 

 84 



ZOOid (<I>of, an animal ; eifios, form), a 

 single individual of a compound organism. 

 138, 234 



Zootham'nium (u>ov, an animal : Od^vcs. 

 a bush) : Figures, 132, 136 : occurrence 

 and general characters, 133 : dimorphism 

 of zooids, 133 : means of dispersal, 133 : 

 characters and mutual relations of species. 



I*" 1 *"* T A 

 JJ! I j4 



Zooxanthell'a (u>ov, an animal : ai/0u?, 

 yellow), 152 



Zyg'ospore (vyoi>, a yoke : cnropd, a seed), 

 applied to a resting zygote formed by the 

 conjugation of similar gametes, 164 



Zygote (^vycoTo?, yoked), the products of 

 conjugation of two gametes : Hetero- 

 mita, 41 : Vorticella, 131 : Mucor, 164 : 

 Vaucheria, 197 : Spirogyra, 198. 



THE END 



K1C1IAKD CLAY AND SONS, LIMITED. LONDON AND BUNGAY 



