and Laboratory Methods. 1347 



demonstration with simple apparatus are ingenious and valuable. Especially 

 worthy of mention in this connection are the methods given for illustrating the 

 processes of circulation and respiration. The text figures are numerous and for 

 the most part copied from standard works. As a whole the book makes a 

 very good impression and, in the hands of a competent teacher, ought to prove 

 an excellent high school text. R. p. 



CURRENT BACTERIOLOGICAL LITERATURE. 



H. W. Conn. 



Separates of papers and books on bacteriology should be sent for review to 

 H. W. Conn, Wesleyan University, Middletown, Conn. 



Migula, W. System der Bakterien. Vol. II. A second volume of Migula's System 



Gustav Fisciier. Jena, looo. , -r, ^ . • i j v 



^ der Bakterien has made its appear- 



ance. The author's original purpose was to collect all species of bacteria which 

 had been described, and, by testing them in culture media in his own laboratory, 

 to make comparative studies and descriptions. This task proved to be wholly 

 impracticable. Many of the species he could not obtain, and many of those 

 sent him were not in condition for study. The book is therefore simply a 

 compilation of descriptions of species as given by the original authors. It is a 

 large work of 1068 pages, with 35 figures, and indicates an immense amount of 

 labor in compilation on the part of the author. h. w. c. 



Beijerinck. Anhaufungsversuche mit Ureum- The very great importance of the fer- 

 bakterien. Cent. f. Bak. u. Par. II, VII, mentation of urea makes it somewhat 

 p. 33, 1901. . .... 



strange that the bacteria producing this 



phenomenon have not been more carefully studied. Until the appearance of this 

 work of Beijerinck very little has been known in regard to the micro-organisms 

 concerned in urea fermentation, a few observations made some time ago com- 

 prising our sole information. The author, however, has investigated the sub- 

 ject, and has described, with excellent figures, five new species of micro-organisms 

 associated with this universal and significant fermentation. These specimens 

 include bacilli, some of which have flagella and others not, and it also includes 

 a Sarcina species which is motile and abundantly provided with flagella ; a 

 somewhat unusual relation. The author also studied the subject from a phys- 

 iological standpoint and concluded that the decomposition of urea is produced 

 by an enzyme, urase. This enzyme is completely insoluble, and is so intimately 

 bound to the body of the bacterium that it cannot be separated from it. 



H. w. c. 



Stutzer. Die Organismen der Nitrifikation. For some years there has been a dis- 



Cent. f. Bac. u. Par. II, VII, p. i68, igoi. ^ v i. c^. i. j ^u is 



' ' ^ ' ^ pute between Stutzer and the Russian 



bacteriologist, Winogradsky, in regard to the nature and the physiological 



properties of the extremely important soil organisms known as nitrifying bacteria. 



Winogradsky, who originally discovered them, has described them as bacteria 



having a most extraordinary sensitiveness to the presence of organic substances, 



