ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 187 



entering the latter puts out haustoria-like processes, which in some cases 

 extend as far as the inner integument. These processes appear to absorb 

 and conduct food material to the embryo. This agrees with Longo's 

 observations on the pollen tube of Gucurbita Pepo, in which there is a 

 special distribution of starch around the haustoria. 



Physiology. 

 Nutrition and Growth. 



Formation of Oxalic Acid by Sterigmatocystis nigra.* — P. G. 

 Charpentier finds that oxalic acid appears in the culture medium where 

 this fungus has grown, but not till after the conidia have been formed,, 

 when the fungus diminishes in weight, the medium has lost its acidity, 

 and the inverted sugar is consumed. He concludes that oxalic acid is 

 not an intermediate product of the breaking up of sugar, but that the 

 fungus, after the medium is exhausted, oxidises its reserves, and thus 

 forms oxalic acid. 



Organic Acids as a Source of Carbon in Algae .f — 0. Treboux 

 describes a series of experiments which lead to the conclusion that 

 organic acids take part in the supply of nourishment even to plants 

 which themselves possess chlorophyll. 



Chemical Chang-es. 



Action of Fungi on Cellulose.:}: — H. C. Schellenberg finds from a 

 study of a series of fungi that none of them can dissolve true cellulose. 

 They dissolve several forms of hemicellulose. The resistance of cellu- 

 loses to the action of the fungi is not the same as their resistance to acids ; 

 it depends rather on their molecular constitution. They are dissolved 

 by the action of a ferment which is also found in the bacteria of butyric 

 acid. There are four distinct ferments which act only on hemi- 

 celluloses. 



Probable Existence of Emulsin in Yeast.§ — T. A. Henry and 

 S. J. M. Auld have studied the action of yeast on glucosides, and have 

 shown that the glucosides which are decomposed by yeast are those which 

 are attacked by emulsin, and further, that the conditions under which 

 these decompositions are affected by yeast, especially as regards tempera- 

 ture, are those which recur in the case of emulsin. Hence they conclude 

 that the glucoside-destroying action of yeast is due to the secretion of 

 emulsin in the cells of the plant. 



Hibsch, Julius — Der Einflusz von Formaldehyde auf Vermehrungsenergie und 

 Gartmgsenergie, sowie auf die Generationsdauer verschiedener Hefearten. (The 

 influence of formaldehyde on the increase and the fermentative ene rgy , as also 

 on the persistence of different species of yeast.) 



Mitt. Oestcrr. Versuchs.-St. Akad. Brauind. Wien t 



Allg. Zeitschr. Bierbr. Malzfabr., 1905, No. 32. 



See also Centralbl. Bakt., xv. (1905) pp. 664-5. 



* Comptes Rendus, cxli. (1905) pp. 367-9, 429-31. 

 t Ber. Deutsch. Bot. Ges., xxiii. (1905) pp. 432-41. 

 X Arch. Sci. Phys. Nat., xx. (Geneva, 1905) p. 574. 

 § Proc. Roy. Soc, Series B, lxxvi. (1905) pp. 568-80. 



