316 INDEX. 



Ulva latissima, structure and mode of reproduction of, i. 225-227 

 Ulva Linza, structure and mode of reproduction of, i. 226 

 Umbilicaria, structure and habitat of, i. 308 

 Upas-tree of Java, causes of the virulence of, i. 426 



fruit of, innocuous, i. 426 

 Uranium, i, 4, 5 



nitrate of, phosphorescence of, i. 67 

 Uranite, yellow, fluorescent property of, i. 66 

 Uredines, structure and habitat of the, i. 277 

 Uredo, structure and mode of reproduction of, i. 277 

 Uredo Candida, or Cystopus candidus, structure, habitat, and mode of 



reproduction of, i. 278 



Uredo linearis, the rust on the leaves and chaff scales of wheat, i. 281 

 Uromyces appendiculatus, or fungus of the common bean, i. 280 

 Usnea, structure of, i. 302 

 Usnea melaxantha, splendour of, i. 304 

 Usnea Taylori, splendour of, i. 304 

 Usnese, brilliancy and wide diffusion of the, i. 304 

 Usnic acid, produced by lichens, i. 303 

 Uva di mare, fruit of, i. 257 



Vacuum tubes, i. 78, note 



electric discharges in, i. 78, 79 

 Valvulina, structure of, ii. 37 

 Vanilla, reproduction of, i. 402 

 Vapours, absorption of radiant heat by gases and vapours, i. 38 



radiation of, equal to absorption, i. 46 

 Variola dealbata, litmus or orchil obtained from, i. 124 

 Vaucheria, character of the genus, i. 218, 224 



structure, habitat, and modes of reproduction of, i. 218 

 Vaucheria marina, structure and habitat of, i. 224 

 Vaucheria sessiles, mode of reproduction of, i. 219 

 Vaucheria velutina, habitat of, i. 224 

 Vegetable world, microscopic structure of the, i. 167 

 Vegetation, i. 167 



effects of light and heat on, i. 168, 169 



the primordial cell, the universal framework or skeleton of the 

 vegetable world, i. 170, 172 



formation of cellular tissue, i. 171, 173 



