ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 641 



M. Van Tieghem further describes two new species of GiMuUna, 

 G. aurea and sessilis, and two of Dictijostelium, D. roseum and lacteum. 



These three genera M. Van Tieghem proposes to erect into 

 a distinct group of Myxomycetes, under the name AcrasiacecB, the 

 whole family being then classified into the following primary 

 divisions : — 



■Di T n 1 (endosporous Myxomycetes proper. 



Plasmodium fused .. < ^ n i- 



(^exosporous CeratiacecB. 



Plasmodium aggregated Acrasiacece. 



The position of the genus Plasmodiophora remains uncertain. It 

 may constitute a third family of the first division, or it may be a type 

 of a third primary division with undivided plasmodium, without either 

 fusion or aggregation, in which case it would form a link between the 

 Myxomycetes and the Chytridinieae. 



The author suggests that the increasing heterogeneity of the 

 Myxomycetes will result in the abolition of the group and the placing 

 of their principal divisions in the various orders of fungi to which 

 their fructification presents the closest resemblance. 



Ferments.* — Mr. D'Arcy Power gives a resume of the present 

 state of our knowledge on this subject, pointing out that as non-mor- 

 phologiQa,l ferments have been shown to exist in very low forms of life, 

 vegetable as well as animal, there does not appear to be any valid 

 reason why the Saccharo- and Schizo-mycetes should not be dependent 

 on a ferment which is secreted by them, and is in reality of the non- 

 morphological type ; for it can scarcely be supposed that the secretion 

 of these substances should cease suddenly and abruptly on reaching 

 the Protophytes and Protozoa. The experiments of Claude Bernard 

 and Kiihne show, in fact, that such is not the case, and that an 

 extract containing a non-morphological ferment can, in some cases 

 at any rate, be obtained from a ferment of the morphological 

 group. 



Fermentation by Sehizomyeetest — In the sixth instalment of 

 his paper on this subject, A. Fitz describes experiments with the fol- 

 lowing nutrient fluids : — calcium lactate, calcium glycerate, and gly- 

 cerin ; the ferment being Pasteur's butyric ferment alone or mixed 

 with other Schizomycetes which also produce butyric acid. The 

 following are the results of four special experiments :— 



1. 100 g. of calcium lactate. Principal product of fermentation : 

 — propionic acid, with small quantities of succinic acid and traces of 

 alcohol. 2. 100 g. calcium lactate, but a different ferment. Products 

 of fermentation : — propionic and normal valerianic acid, with traces 

 of alcohol. 3. One-half k. calcium lactate, with Pasteur's butyric 

 ferment. Products : — Butyric acid, ethyl- and butyl-alcohol in nearly 

 equal quantities. 4. Three k. calcium lactate, with the same ferment 



* St. Bartholomew's Hospital Eeports, xvi. (1S80). 



t Ber. deutsch. chem. Ges., xiii. (1880) pp. 1309-12. See Bot. Centralbl., vi. 

 (1881) p. 2. 



