ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 497 



not only to the chemist, botanist, and biologist, but also to the brewer, 

 distiller, yeast-maker, and all such as are engaged in fermentation 

 industries. 



The present edition has been not only thoroughly revised, but in- 

 corporates new features and additioual matter, among which are an 

 examination of several English high fermentation yeasts, observations on 

 the changes which yeast undergoes during its use in factories, descrip- 

 tions of recently discovered yeasts, of the organisms occurring in milk, 

 and the use of pure cultures of lactic acid bacteria in dairies and dis- 

 tilleries. The volume is copiously illustrated, and contains an ample 



bibliography. 



Myxomycetes. 



Dictyostelium mucoroides.* — G. A. Nadson finds this organism easy 

 to cultivate on sterilised dung. It does not liquefy gelatin ; it is dis- 

 tinctly aerobic, and prefers a slightly alkaline medium ; fluid media are 

 not favourable to its growth. It is usually accompanied by a variety of 

 bacteria, some of which have a decidedly favourable influence on its 

 development. Its most usual associate is Bacillus fluoresceins liquefaciens 

 Flugge, among its spores. Between these two organisms there seems to 

 be a kind of symbiosis. The bacillus advantages the Dictyostelium by 

 increasing the amount of ammonia in the substratum ; while the latter 

 supplies the former with the organic substances required for its com- 

 plete development. 



Protophyta. 



a. Schizophyceae. 



Cyanophycese.f — In a general review of the structure of this family, 

 Herr E. Zacharias states that the cell-contents are differentiated into a 

 colourless central body and the coloured protoplasm which surrounds it 

 on all sides ; the latter is not properly a chromatophore. There is no 

 evidence of a colourless border of protoplasm surrounding the coloured 

 portion. The central body appears to be often homogeneous, or at 

 most finely granular. It is often very irregular in form ; whether it 

 occasionally has a framework is uncertain ; nor has the presence of 

 vacuoles been established. Two kinds of substance are imbedded in the 

 protoplasmic matrix, cyanophycin granules and central granules. The 

 former swell up quickly in dilute hydrochloric acid and are strongly 

 stained by acetic-carmin ; they appear to be a reserve-substance. The 

 central granules are clearly revealed in dilute hydrochloric acid as 

 shining bodies ; they appear to be imbedded in the central body after 

 the manner of nucleoles, chiefly in its superficial portion. In addition 

 to these, there is usually in the central body a varying quantity of a 

 substance resembling glycogen ; and in some cases oil-like drops and 

 crystals. 



Hormogoneae of Denmark.} — J. Schmidt has published a monograph 

 of the Danish species of this section of Cyanophycese, of which he makes 

 118, including 2 new ones, Anabsena baltica and Microchaete purpurea. 



* Scripta Botanica (St. Petersburg), xv. (1899). See Bot. Centralbl., lxxxii. 

 (19C0) p. 227. 



t Abhandl. a. d. Geb. Naturw. Ver. Hamburg, xvi. (1900) 50 pp. and 1 pi See 

 Bot. Ztg., lviii. (1900) 2" Abt., p. 135. 



X In Danish. Copenhagen, 1899. See Journ. of Bot., xxxviii. (1899) p 232. 



