386 BACILLI WHICH CAUSE PUTREFACTION. 



oxygen wliicli is present has been used up by the pre- 

 liminary development of the aerobes, and as soon as the 

 nutrient medium has become loaded with the products 

 of tissue change and of the fermentative action of these 

 . bacteria, with carbonic acid, hydrogen, and other gases, 

 the most favourable conditions conceivable for the 

 growth of the anaerobes are produced, and from this 

 point they multiply rapidly. If the access of air and 

 the amount of oxygen in the nutrient substratum is 

 from the first limited, as is" the case in the interior of 

 dead animals, and more especially in those which have 

 died of asphyxia, the anaerobes occupy the foremost 

 place from the beginning. Up till recently only the 

 bacilli of malignant osdema of symptomatic anthrax, of 

 tetanus, and of the butyric acid fermentation, have been 

 known as typical anaerobes. Some other anaerobic 

 bacilli have been isolated in the course of the last few 

 years in the author's laboratory, and among these are 

 some which break up egg albumen energetically, and 

 Methods of which produce intensely foul-smelling gases. These 

 can be obtained pure by the aid of the ordinary gelatine 

 or agar plates if kept permanently in an atmosphere 

 of pure hydrogen. They also develop if a thick layer 

 of a solid nutrient material is employed, in which case 

 an upper portion, several centimetres in breadth, 

 remains completely free from colonies. 



The organisms which have been as yet isolated are 

 for the most part large bacilli which form large, highly 

 refracting spores in the threads, or after preliminary 

 development of clostridium forms. At times they pre- 

 sent the appearance of fine rods with large terminal 

 spores. The majority do not produce dense and cir- 

 cumscribed colonies, but branched and knotted' masses ; 

 gelatine and blood serum are liquefied, and the cultiva- 

 tions, give off a foul smell varying in degree and 

 character in different cases. An accurate description of 

 some of the bacilli which belong to this group will be 

 shortly published. 



