250 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



comitant of secreted matters, cominsj into contact with nitroo-- 

 enous fluids, gradually adapted itself to retain its vitality 

 and take on tin absorptive function. 



A valuable contribution to microscopical diagnosis in bot- 

 any is M. Packenham Edgeworth's compact and convenient 

 book on "Pollen," just issued by Hardwicke, London. It is 

 illustrated by twenty-four plates, from drawings by the au- 

 thor, and these afford abundant evidence of the taxonomic 

 importance of pollen; and the book is not only valuable for 

 reference to adepts, but still more extensively interesting to 

 amateurs. The work is exceedingly meritorious and full of 

 valuable facts, and it is creditable to its author and British 

 botany. 



M. Henneguy, in a paper recently read before the French 

 Academy, states that Volvox minor is dioecious, while the V. 

 globator is monoecious. The former is a colony of unicellular 

 alga?, sometimes composed of vegetable cells only, having 

 young colonies in their interiors, sometimes containing male 

 elements (androgonidia), situated in the thickness of the 

 gelatinous wall, and sometimes female colonies, containing 

 only gynogonidia, or oospheres, in the interior. 



The androgonidia are formed at the expense of a vegeta- 

 tive cell. The gynogonidia likewise spring from a differen- 

 tiation of a vegetative cellule. The fecundation is effected 

 through the liberation of antheroids by the dissolution of the 

 antheridial wall. These volvoces, male, female, and neuter, 

 seek the light and keep near the surface of the water; but 

 when the female colonies are fecundated, they get away from 

 the surface. 



In a paper read lately (September 26) before the Crypto- 

 gamic Society of Scotland, Mr. Worthington Smith, F.L.S., 

 explains very fully the structure of the common mushroom. 

 The entire substance is made up of excessively small blad- 

 der-like cells, one and a half billion to every ounce of the 

 mushroom's weight. The spores are produced apparently 

 two at a time at the base of each basidium : there are really 

 four, for at the time of dropping off the first tw T o, the last 

 two appear. These spores will, on germination, reproduce 

 the species, but their life is very short. Once germinated, 

 however, and forming the spawn, or mycelium, this has great 

 tenacity of life, and is commonly, if not always, perennial. 



