192 THE AMERICAN MONTHLY [Jul 



ganisms were less able afterwards to adapt themselves to 

 a less concentrated medium. (Bull. Acad. Roy. Belgique, 

 1899, p. 81). 



Yeast. — According to C. C. Lintner yeast has the power 

 of forming alcohol and carbonic acid at the expense of its 

 own body, without the addition of sugar. The material 

 for this self fermentation is glycogen which is first con- 

 verted into grape sugar and then into alcohol and car- 

 bolic acid. (Centralb. Bakt. u. par. abt. 5 : 793.) 



Cell-membrane of the Mucorineje. — According to 

 M. L. Mangin the cell-wall in the MucorineaB presents char- 

 acters that are different from other Oomycetes. In Per- 

 onosporesB and Saprolegniese the cell-wall is partly formed 

 of callose but it is usually wanting in Mucorineje. It con- 

 sists of cellulose associated with pectic compounds. The 

 cellulose is more resistant to chemical agents. (Jour, de 

 Bot. 13 : pp. 209, 276, 307, 339, 471, pi. 2, 7 figs). 



Miscellaneous Notes on Microscopy. 



JOHN H. COOKE, F. L. S. 

 Water Bugs. — The residua and strainings obtained 

 from ordinary tap water will provide the microscopist with 

 an abundance of material for examination. Among the 

 organisms that he will probably meet with are the fat 

 little rotifer, Triarthra longiseta, hobbling along on his 

 long delicate stilts in company with the pretty, little, long 

 spined Anurea longispina. The Vorticellidse and Ento- 

 mostraca are often in great force, with diatoms and des- 

 mids innumerable. Dinobryon sertularia, a curious com- 

 pound flageollate organism, like animated ears of barley, 

 though not so numerous, are invariably present in greater 

 or lesser numbers. A bag made of several thicknesses 

 of very fine muslin and tied on the water tap, so that the 

 water strains gently through it, is a rough and ready, but, 

 on the whole, a satisfactory way of capturing them, 



