3 i8 INDEX. 



Vegetation : chemical functions, i. 419 

 cellulose, i. 419, 420 

 starch, i. 420 



diastase and dextrine, i. 420, 421 

 sclerogen, or colouring matter of wood, i. 421 

 sugar, i. 421 



oils, resins, and wax, i. 422, 423 

 albumen, fibrin, and casein, i. 423 

 raphides, i. 424 

 milk sap, i. 425 



poisons, i. 425, 426 

 food and other purposes, i. 426 

 alkaloids, chemical structure of, i. 427 

 colouring matter of flowers, chemical nature of, i. 428, 429 

 water secreted by plants night and morning, i. 429 

 electricity developed by plants and flowers, i. 430 

 irritability of the tissxies of plants, i. 430 



light the most universal and important exciting cause in 



the vegetable world, i. 431 



Velella spirans, structure and modes of locomotion and reproduction of, 

 ii. 114-116 

 food of, ii. 116 

 habitat of, ii. 117 



Velellidse, characters of the order, ii. Ill, 114 

 Venus, the planet, spectrum of, i. 158, 162 



Veratrum album, or white hellebore, poisonous alkaloid of, i. 427 

 Verrucariei, structure of, i. 310 

 Verrucaria muralis, structure and habitat of, i. 310 

 Verrucaria variolosa, structure and development of, 299, 300 

 Vibrissea, motions of the sporidia in, i. 292 

 Vibrios found in dust from Egypt, ii. 65 



agents in the decomposition of organic matter, ii. 66, 67 

 difference between vibrios and mycoderms, ii. 66 

 extreme tenacity of life of the vibrios, ii. 67 

 Vine, fungus constituting the mildew of the, i. 295, 297 

 Vinegar plant, fungus producing the, i. 288 

 Virgularia juncea, ii. 129 



Virgularia mirabilis, mode of reproduction of, ii. 129 

 Virgularise, structure and mode of reproduction of the, ii. 129 

 Vis viva, or impetus, i. 26, 27 

 heat generated by, i. 27 

 combustion, a case of, i. 30 



