84 ATLAS OF BACTERIOLOGY. 



USCHINSKY SOLUTION. 



Albumin. Ash. Total. 



Cholera, old 48.13 7. 14 55.27 



Cholera, Hamburg, winter of 1892. 35.75 13.70 49.45 



Cholera, Paris 65.63 9.37 70.00 



Cholera, Shanghai 47. 50 1 1. 64 59. 14 



Cholera, Hamburg, autumn of 



1893 34.37 14.74 49.11 



This result again shows how dangerous it is to dis- 

 tinguish two varieties by relying upon a single chemi- 

 cal or biological reaction. Some of these varieties 

 need merely acquire the power of forming thick cell 

 membranes in Uschinsky solution in order to explain 

 these remarkable differences. How easily, for exam- 

 ple, could a writer be led, from these figures, to re- 

 gard the bacilli of the Paris cholera as a distinct spe- 

 cies, because they contain almost twice the amount 

 of albumin in Uschinsky solution as those of the 

 Hamburg cholera. 



So far as I know the spores of bacteria have not 

 been closely analyzed, but from the analogy to the 

 spores of mould fungi we may expect them to contain 

 a diminished amount of water. 



C. The Vital Conditions of Bacteria. 



1. NUTRIENT MEDIA. 



While a number of schizomycetes have been found 

 hitherto only in the human or animal organism, and 

 therefore appear to be strict parasites (for example, 

 spirillum Obermeieri), the majority of parasitic vari- 

 eties can also be cultivated, either readily (for exam- 



