and Laboratory Methods. 1811 



Upon concluding this review the author's attention was drawn to a few appli- 

 ances and methods not described herein. Their inventors are: Zettnoiv (1894), 

 Migiila (1895), Klem (1898), Epstein (1898), Bonibicci(^%)1), and Turro (1902). 

 These apparatus differ but slightly from those already discussed, and the methods 

 are all based upon the principles treated in the review. Space does not permit 

 here a detailed description of same, but the references are given in the biblio- 

 graphy. 



Classification of the Methods Reviewed According to the Purpose for 

 Which They are Most Adapted. 



The inventors of the existing methods and apparatus for the cultivation of 

 anaerobic bacteria devised their apparatus and introduced their methods for cer- 

 tain specific purposes. While one set of apparatus may give perfect satisfaction 

 in one line of work, it may be almost worthless elsewhere. This fact is in per- 

 fect accordance with the strong tendency for the division of labor and occupa- 

 tion which has so completely revolutionized the economic, industrial and scien- 

 tific world of the past century. The study of anaerobic bacteria involves a series 

 of experiments, the different stages of which vary in character. And in order to 

 obtain rapid and satisfactory results, it is necessary that the methods employed 

 for this work should be chosen in accordance with the purpose of their respec- 

 tive inventors. With the endeavor, then, of facilitating the proper selection of 

 methods the following classification has been made : 



1. Methods for the determination of the presence of anaerobic bacteria in a 

 given substance. 



2. Methods for isolating anaerobic bacteria. 



3. Methods for growing pure cultures of anaerobes on different media. 



4. Methods for the propagation of pure cultures and for the preservation of 

 stock cultures. 



5. Methods for the preparation of toxins. 



1. Methods for the determination of the presence of anaerobic bacteria. 



The simplest and most practical methods for the study of the relation of bac- 

 teria to free oxygen consist of cultures in deep layers of solid medium as recom- 

 mended by Liborius (V. a.), the use of Smith's fermentation tube (V. f.) (Fig. 

 50) and the use of Wright's apparatus (V. e. Figs. 46 and 47). 



2. Methods for isolating anaerobic bacteria. 



To this class belong most of the methods that permit the use of solid media. 

 In laboratories where apparatus like that of Novy (II, Fig. 24), Gabinsky (II, Fig. 

 23), and others are within reach, the use of plate cultures in hydrogen atmos- 

 phere is most satisfactory. In the absence of large apparatus cultures in deep 

 layers (V. a.), Esmarch roll cultures for anaerobic bacteria as recommended by 

 Esmarch and Schill (V. a.), Buchner's method (III, Fig. 30) are of value. 



3. Methods for growing pure cultures of anaerobic bacteria on different media. 

 As in the study of aerobic, so also in that of anaerobic cultures the species can 



be determined only by their cultural characteristics. For the determination and 



