ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 301 



Protophyta. 



Nucleus in Yeast-cells.* — Herr F. Krasser has endeavoured care- 

 fully to test the accuracy of the statements of Schmitz, Strasburger, 

 and De Bary of the presence of a nucleus in the cells of Saccharomyces 

 cerevisise, biit mth entirely negative results, using as staining mate- 

 rials haematoxylin and hfematein-ammonia, as well as other reagents, 

 such as carmine, saffranin, &c. With the ammoniacal staining mate- 

 rials he was sometimes able to colour granular structures, but these 

 could not with certainty be recognized as nuclei, especially as they 

 occurred also in cells from which the nuclein had been removed. 

 The author states that the nucleus always contains nuclein, but the 

 converse is not always true, that the presence of nuclein indicates a 

 nucleus, the facts rather pointing to the conclusion that in the cells 

 of yeast the nuclein is distributed through the protoplasm. 



Nomenclature of ScMzomycetes.t — Herr H. Buchner considers 

 that the various species of Schizomycetes are constant, but that they 

 are subjected to a great variety of " growth-forms," according to their 

 vital conditions. In order to avoid the confusion at present pre- 

 vailing in their nomenclature, he proposes to retain the Latin names 

 Micrococcus, Bacillus, &c., to designate the species, and some such 

 scheme as the following for the " growth-forms." 



A. Forms isolated in their growth. 



SpTierical form. The longitudinal and transverse diameters equal. 

 Oval form. Longitudinal not more than double transverse 



diameter. 

 Short-rod form. Longitudinal 2-4 times transverse diameter. 

 Long-rod form. ., 4-8 „ „ 



Filiform form. Longitudinal more than eight times transverse 



diameter. 

 Semi-helix or Comma form. A very short helix of not more than 



a single circuit. 

 Long-helix or Spiral form. Two or more circuits of the helix. 

 Spindle form. Eod with fusiform ends. 

 Oval-rod form. Ends less pointed than spindle -form ; longitudinal 



2-4 times transverse diameter. 

 Clttb form. Rod with end thickened on one side. 



B. Forms united in their growth. 



Double-sphere form. Union of two spheres. When the separation 



is barely indicated : — Hour-glass form. 

 Boio-of -spheres form. Union of spheres up to eight. When the 



separation is barely indicated : — Torula form. 

 Filament-of-spheres form. Union of more than eight spheres. 



When curved : — Bosette form. When the separation is barely 



indicated : — Torulose filaments. 



* Oestcr. Bot. Zeitschr., xxxv. (1885) pp. 373-7. 



t SB. Gesell. Morphologie u. Physiologie Miinchen, June 23, 1885. See 

 Bot. Centralbl., xxiv. (1885) p. 258. 



