ZOOLOGY AND BOTANY^ MICROSCOPY, ETC. 633 



drical. It is of interest in reference to the question of the polymorphism 

 of the Chlorophycese, exhibiting evidently a change of form resulting from 

 altered vital conditions, since all intermediate stages occur between the 

 typical and the varietal form. Stichococcus hacillaris assumes a similar 

 form when it occurs as gonidia in the lichen- th alius of the Calicieee. 



Remarkable Flos-aquse.* — Dr. G. B. De Toni records the observa- 

 tion of a remarkable scum or " flos-aquaa " observed on the surface of the 

 water in an aquarium in the botanic garden at Parma. It consisted of 

 an enormous number of biciliated zoospores in very active motion, which 

 apparently could not be derived from any Cladophora or other alga 

 belonging to one of the higher groups. On germinating the zoospores 

 gave birth to a pseudo-pediastroid organism apparently identical with 

 DictyospJi aerlum Ehrenbergianum. 



Composition of " Muffe." f — Prof. E. Perroncito and Dr. L.Varalda 

 have examined the nature of the substance known as muffe (mould) used 

 largely for curative purposes in the district of Valdieri in Piedmont. 

 It is found as a scum on the surface of hot springs of a temperature from 

 56° to 69° C. more or less impregnated with sulphuretted hydrogen, and 

 is largely cultivated on the surface of wet inclined rocks. They find it 

 to consist almost entirely of Lcpfothrix valderia, among which are inter- 

 spersed filaments of an Oscillaria and cells of a Glceocapsa. The fila- 

 ments of the Leiitoihrix have a diameter of from ' 8-1 ' /x. 



Sacoharomyces minor. J — Sig. G. Arcangeli maintains that this 

 organism is the chief factor in panic fermentation. It differs from S. 

 cerevisise chiefly in the size of its cells, which are considerably smaller. 

 He describes various nutritive media on which he was successful in 

 obtaining pure cultures of this ferment : — a mixture of gelatin and 

 honey, Koch's nutrient gelatin, and agar-agar. In Koch's gelatin and 

 agar-agar, it developes chiefly on the surface of the substratum, forming 

 a white scum. 



The author obtained an organism closely resembling S. minor, and 

 apparently identical with it, from the fermentation in water of the aril 

 of the seeds of Eunjale ferox, which contain a large quantity of 

 mucilage. 



Spores of the rerments.§ — M. E. Wasserzug states that in 1868 

 the spores of what was known under the name of Mycoderma vini were 

 observed for the first time by M. de Seynes. Shortly afterwards Eeess 

 cultivated various species of the genus Saccharomyces, not in a liquid, but 

 on slices of carrot, or potato, and found that the spores formed easily. 

 On account of their endogenous formation, and because there were usually 

 four in a cell, Eeess placed the Saccharomycetes among the lower 

 Ascomycetes. The author's method for studying the spores of the 

 Saccharomycetes is to sow them on small pieces of filter-paper. Steriliza- 

 tion having been effected, the spores begin to form in about twenty- 

 four hours at a temperature of 25°. The author was able to study ten 

 species obtained from various kinds of wine and beer; in each case 

 purification was made with care by successive cultures on gelatin. In 

 order to render the ascospores plainly visible, a weak solution of eosin 



* Kuov. Gioru. Bot. Ital., xx. (1888) pp. 295-7. 

 t Notarisia, ii. (1887) pp. 333-7. 

 X Nuov. Giorn. Bot. Ital., xx. (1888) pp. 303-6. 

 § Bull. Soc. Bot. France, xxxv. (1888) pp. 152-7. 



