304 INDEX. 



Pteris serrulata : archegonium of, i. 338 



Puccinise, structure and habitat of the sub-order, i. 276, 277 



Puccinia Amorphse, spores of, i. 276 



Puccinia Fabse, structure, habitat, and method of reproduction of, i. 280 



alternation of generations of, i. 280 

 Puccinia G-raminis, spore-cases of, i. 280 

 Puccinia lateripes, spores of, i. 276 

 Puff-balls of the meadows, i. 267 

 Purple dyes, i. 123, 124 



Pycnogonoi'dea, or spider crabs, structure and habitat of, ii. 211 

 Pyrosomidse, structure and mode of reproduction of the, ii. 225 

 Pyxinei, characters of the, i. 307 



Quartz, rock-crystal the purest form of, i. 17 



certain thickness of, not transparent to invisible rays of light, i. 65 



axis of symmetry of, i. 72 



aqueous solution of, i. 110 



characteristics of the, i. Ill 

 Queen conch, shell of, ii. 234 

 Quinine, structure of, and whence obtained, i. 427 

 Quinqueloculina Bronniana, form of, ii. 228 



Eadiation of light and heat, i. 34, 35 



effects of, i. 35, 36 



generally independent of colour, i. 36 



Professor Tyndall's experiments, i. 38 



experiments showing radiation to be equal to absorption, i. 46 



dynamic radiation, i. 49 



absorption a phenomenon irrespective of aggregation, i. 53 

 Radicles, compound, i. 106 

 Ramalina calicaris, gluten of, i. 303 

 Ramalina polymorphum, dyes obtained from, i. 303 

 Eamalina xopulorum, dyes of, i. 303 

 Raphides, structure and formation of, i. 424, 425 

 Red Sea, foraminifera in the, ii. 51 



