254 INDEX. 



Acetylene, chemical composition of, i. 128 



Achlya prolifera, structure and reproduction of, i. 220 



Acids, their affinity for alkalies, i. 96 



Acineta, structure and mode of reproduction of, ii. 77, 78 



food of, and mode of seizing it, ii. 78 

 Acorn-shell, structure of the, ii. 213 

 Acrocarpi, characters of the group, i. 328 

 Acrocladia mammillata, spines of the, ii. 180, 181 

 Acrostichese, characters of the, i. 359, 360 

 Actinia sulcata, structure of, ii. 132 



Actinian polype, structure and mode of reprodiiction of, ii. 130, 131 

 Actinian zoophytes, characters of, ii. 130, 131 



thread-cells, ii. 132 



structure of, ii. 134-136 

 Actinism of star-light, i. 55 



of moon-light, i, 55 



of sun-light, i. 56 



Actinocyclus undulatus, structure of, i. 199, 200 

 Actinomma drymodes, structure of, ii. 21 

 Actinophrys sol, structure and reproduction of, ii. 16-18 



certain degree of instinct exhibited by, ii. 18 



its enemy, the Amoeba, ii. 18 

 Adder's tongue fern, i. 365 

 Adiantiese, characters of the groups, i. 358 



Adiantum Capillus-Veneris, or maiden's-hair fern, structure and habi- 

 tat of, i. 359 



Adriatic sea, Foraminifera in the ooze of the bed of the, ii. 51 

 Adularia, or moonstone, fluorescent property of, i. 66 

 u-Ecidium, characters of, i. 280 

 ^Egean sea, zones of Algae in the, i. 259 

 JEthalium septicum, structure and habitat of, i. 270-272 



Amceba-like motions of, i. 270 



mode of reproduction of, i. 271 

 Affinity, chemical, of kind and of degree, i. 95 



relation between chemical affinity and mechanical force, i. 98 

 Agaricini, the order, i. 261 

 Agaricus, the genus, i. 261, 263 



structure of the, i. 263 

 Agaricus arvensis, spawn of, i. 262 

 Agaricus campestris, or common mushroom, i. 261 



structure and mode of reproduction of, i. 261 

 Agaricus gardneri, luminosity of, i. 264 



