258 INDEX. 



Arum, structure and mode of reproduction of, i. 388 



water secreted by the, at night, i. 429 

 Arundo Donax, size of the, i. 386 



Ascaris lumbricoides, structure and mode of reproduction of, ii. 147 

 Asci, or sporidia sacs, of Ascomycetes, i. 290 

 Ascidia virginea, structure, food, and habitat of, ii. 224, 225 

 Ascidians, or Tunicata, character of, ii. 222 



compound or social gelatinous, ii. 222 



star-like, ii. 224 



Ascomycetes, structure of, i. 290 

 Ascophora elegans, fructification of, i. 226 

 Ashes, i. 14 



Aspergillus dubius, spores of, i. 286 

 Aspergillus glaucus, spores of, i. 286 

 Asphalt, sources of, in various parts of the world, i. 126 

 Aspidise, characters and habitat of the group, i. 346, 348 

 Asplenieae, characters and habitat of the group, i. 351, 352, 353 

 Asplenium lanceolatum, structure, fructification, and habitat of, i. 354 

 Asplenium marinum, structure and habitat, i. 355, 356 

 Asplenium Kuta-muraria, or wall rue, structure, habitat, and reproduc- 

 tive organs of, i. 353, 354 

 -Asteroidea, or star-fishes, characters of the, ii. 169 



fossil star-fishes, ii. 174 

 Athyrium Filix-fcemina, or lady fern, herbaceous caudex of, i. 340 



structure and fructification of, i. 352, 353 

 Atlantic Ocean, profound depths of, north and south, ii. 49 



foraminifera at great depths in the, ii. 49, 50 

 Atmolysis, or method of analysing gases, i. Ill 



Atmosphere, effect of the heat radiated by the moon on the higher regions 

 of the, i. 55 



opalescence of the, and its effect on the chemical power of the sun's 

 light, i. 55 



causes of this opalescence, i. 55 



its permeability to every kind of chemical rays, i. 58 

 Atmosphere of the sun, thirteen terrestrial substances in the, i. 59 

 Atolls, or coral lagoons, ii. 140 



Atoms or molecules of matter, power of atoms of matter on the rays of 

 the solar beam, i. 58 



aggregation of matter by electricity, i. 74 



effect of the physical forces on molecular arrangement, i. 90, 91 



proof of the individuality and polarity of the atoms of matter, i. 91 



effect of motion, i. 91 



