INDEX AND GLOSSARY 



503 



Vestige, vestigial (vestigium, a trace), 

 applied to any structure which has be- 

 come atrophied or undergone reduction 

 beyond the limits of usefulness, 118 

 VWrio(vibro, to vibrate), 86, 88, (Figure) 

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

 plied to the layer of ccelomic epithelium, 

 or of peritoneum, covering the intestine 

 and other internal organs, 274 

 Visceral ganglion, Mussel, 362 

 Vitelline (vi tellies, yolk) membrane, the 



cell-membrane of the ovum, 257 

 VolVQX (volvo, to roll), 264 (Figures) 

 VORTICELLA (diminutive of -vortex, an 

 eddy): Figure, 127: occurrence and 

 general characters, 126 : structure, 126 : 

 asexual reproduction, 131 : conjugation, 

 132 : means of dispersal, 132, 134 : encys- 

 tation, spore-formation, development, 

 and metamorphosis, 133 



W 



Waste-products, 33 

 Water of organization. 5. 29 

 Whorl of leaves, 205 

 Wood. See Xylem. 

 Work and Waste, 14 



Yeast, 71 



Yeast-plant. See Saccharomyces. 

 Yellow-cells of Radiolaria, 154 

 Yolk-granules or spheres. 68, 233, 256 



Zoogloe'a (d>oi'. an animal : yAoca, glue), 



85 

 Zooid (tjaov, an animal : elSo?, form\ a 



single individualof a compound organism, 



135. 234. 

 DOthE 



v, wood), the inner portion of 

 a vascular bundle, 417, 450, 463 



Zootham'nium (&ov, an animal : 0<j/uu/o?, 

 a bush) : Figures, 134, 138 : occurrence 

 and general characters, 135 : dimorphism 

 of zooids, 135 : means of dispersal, 136 : 

 characters and mutual relations of species, 



Zooxanthcll'a (&ov, an animal : ai>06<;, 

 yellow), is4 



Zyg'ospore (fwydi/, a yoke : trnopd, a seed\ 

 applied to a resting zygote formed by the 

 conjugation of similar gametes, 166 



Zygote (fvywros, yoked), the products of 

 conjugation of two gametes : Hi tero- 

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

 Vaucheria, 174 : Spirogyra. 198 



THE END 



