ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 203 



plant confirms this view, as the ascospores are produced and scattered 

 just when the young fruit is at the stage of infection. The production 

 of Monilia spores goes on until July or the beginning of August, when 

 next year's male catkins begin to form. Schellenberg names the fungus 

 SderoUnia ConjJi. He has found the disease rather wide-spread in 

 Switzerland. 



New Parasite on Cherry-leaves.* — N. Speschnew describes a 

 fungus which he determines as Ovulariopsis persicina sp. n. The 

 conidial form of the fungus only has been met with. The hyphge- 

 which grow on the upper surface of the leaf penetrate the epidermis, 

 and can be traced in the intercellular spaces to the lower epidermis. 



Yeast Plant. — Fred Mutchler f finds that the cytoplasm of the 

 yeast-cell is more or less reticulated, vacuolated, or areolated ; the 

 nucleus occupies the centre of the cell, and is comparatively very large, 

 with a distinct nuclear membrane ; in close association with the nucleiis 

 are 6-10 small but definite granules. No evidence of karyokinesis was 

 observed ; the division is believed to be direct. 



The effect of various substances — metals, formalin, hydrogen per- 

 oxide, acids, alcohol, and anaesthetics — was tested on the yeast, and as it 

 remained constant, the conclusion drawn is that Saccharormjces Cerevism 

 is a stable species ; that variation in form is due to the inherent nature 

 of the cell ; that variation in size and rate of growth is produced by 

 changes in the culture conditions ; and that anaesthetics do not per- 

 manently destroy the growth or reproduction of this species. 



Th. Bokornyl has made a study of the dividing line between life 

 and fermenting power in the yeast-cell. When treated with poisons it 

 has been found that the enzymes are affected in the same way as the 

 protoplasm, but that the effect is weaker. The author set himself the 

 task to find the exact quantity of poison that would kill the proto- 

 plasm without injuring the enzyme. Those used were sulphuric acid, 

 formaldehyde, and sublimate. He was able to estimate in each case the 

 exact amount of the poison for a given quantity of yeast that left 

 the enzyme still capable of fermentative action while destroying the 

 yeast-cell. 



Polymorphism of Colletotrichum Janezewskii.§ — B. Namyslowski 

 found this fungus parasitic on the stalks, occasionally on the leaves, of 

 Poa trivialis, where it forms small pustules. The spores, which are 

 fusiform and somewhat bent, were grown in artificial cultures, where they 

 produced a septate mycelium with chlamydospores at the tips of the 

 branches. From some of the hyphae were formed conidiophores on 

 which were borne the same conidia as in the original pustules. An 

 attempt to reinfect Poa trivialis was unsuccessful. 



* Monit. Jard. Bot. Tiflis, livr. 3 (1906) pp. 1-5 (Russian). See also Bot. Cen- 

 tralbl., cii. (1906) p. 612. 



t Journ. Medical Research, Boston, xvi. (1905). See also New Phytol., v. (1906) 

 p. 250. 



X Arch. Ges. Phys., cxiv. heft 11-12 (1906) pp. 535-44. See also Bot. Centralbl., 

 civ. (1907) p. 7. 



§ Bull. Acad. Sci. Cracovie, Classe Sci. Math. Nat., 1906, pp. 254-7 (1 pi.). 

 See also Bot. Centralbl., civ. (1907) pp. 93-4. 



