ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 371 



in fresh-water. Fischerella grows in moist earth, on wet stones, and in 

 hot springs. Stigonema grows free-floating or on wet stones. It is 

 usually much wider than either of the other two genera ; and is often 

 composed of several rows of cells, which are usually more rounded than 

 in IJapaJo siphon. 



. Gonium pectorale.* — 0. Pliimecke discusses the nutrition of the 

 Volvocacese, and describes the water-bloom of Gonium pectorale. The 

 latter occurred in an aquarium at Neukolln, and showed 300-400 

 colonies in 1 c.cm. of water. The local conditions and the accompany- 

 ing organisms lead to the conclusion that 67. pectorale when developed 

 in masses, absorbs organic substances for its nutrition, and is therefore 

 " mesosaprob." The decline of Gonium was accompanied by a decrease 

 in the other organisms. Myxotrophy is a widely distributed mode of 

 nutrition among many of the Yolvocacea? in a natural state, as has been 

 shown by ecological investigations as well as by laboratory experiments. 



Eudorina elegans.t — "W. Conrad writes on Eudorina elegans Ehr., 

 and gives details of its structure which have been hitherto unknown. 

 The ccenobium possesses a marked longitudinal axis : it is ellipsoidal 

 and slightly truncate at the farther end. Its thirty-two cells lie in five 

 series across the axis of the ccenobium, consisting of four at each of the 

 two poles and eight at the equator. The size of the eye-spot decreases 

 greatly from the near to the farther cell-series. At the base of the 

 flagellum was observed a common membrane-funnel, but no thickening. 

 The structure of the sheaths strongly resembles that of Volvox ; it is 

 composed principally of pectin compounds. The single cells are con- 

 nected with one another by 2-4 delicate strands of protoplasm, which 

 are onlv visible after stainin°;. 



Cladostephus.J — C. Sauvageau publishes the third and last volume 

 of his great work on the Sphacelariaceas. In it he deals with the genus 

 Cladostephus, its morphology, structure, distribution, with the same 

 detail as was shown in the two previous volumes. The European 

 species C. verticillatus and G. spongiosis are first discussed, and then 

 the exotic species, of which the author recognizes three as being good, 

 and two as " species inquirendas." The remaining published names are 

 regarded as synonyms and placed accordingly. Diagnoses are given. 

 The last chapter discusses the different groups of Sphacelariaceaj, as 

 defined and treated in the body of the work. They are founded on 

 the mode of origin of the branches and the presence of secondary 

 growth, a system which conforms to the affinities of the species among 

 themselves. The whole work is fully illustrated by text-figures. The 

 various chapters have appeared from time to time in the Journal de 

 Botanique in much the same form as here published. 



* Ber. Deutsch. Bot. Gesell., xxxii. (1914) pp. 131-6. 

 t Recueil lust. Bot. L. Errera, ix. (1913) pp. 321-43. 



X Remarques sur les Sphacelariacees. Bordeaux : 1914, fasc. iii. pp. i xii, 

 481-634 (figs.). 



