296 BACTERIA 



The Pseudo-diphtheria Bacilhis.^ Loffler and Hoffman 

 described a bacillus having the same morphological charac- 

 ters as the true Bacillus diphtheri(Bj except that it had no 

 virulence. Roux believes this is merely an attenuated diph- 

 theria bacillus. It is frequently found in healthy throats. 

 The chief differences between the real and the pseudo- 

 bacillus are : 



1. The pseudo-bacillus is thicker in the middle than at 

 the poles, and not so variable as the Bacillus diphtherice. 

 Polar staining is absent. 



2. Its growth on potato reveals cream-coloured colonies 

 visible in a couple of days; the real bacillus is invisible. 



3. The pseudo-bacillus will not grow at all anaerobically 

 in hydrogen, but the Bacillus diphtheria is able to do so, 



4. There is the great difference in virulence. 

 Suppuration. This term is used to designate that general 



breaking down of cells which follows acute inflammation. 

 An ** abscess " or *' gathering " is a collection, greater or 

 smaller, of the products of suppuration. The word pus is 

 generally used to describe this matter. We may have such 

 an advanced inflammatory condition in any locality of the 

 body, and it will assume different characters according to 

 its site. Hence there are connected with suppuration, as 

 causal agents, a variety of bacteria. Pus is not matter con- 

 taining a pure culture of any specific species, but, on the 

 contrary, is generally filled with a large number of different 

 species. The most important are as follows : 



I. Staphylococcus pyogenes aureus. These are micrococci 

 arranged in groups, which have been likened to bunches of 

 grapes. They are the common organisms found in pus, and 

 were with other auxiliary bacteria first distinguished as such 

 by Professor Ogston, of Aberdeen. There are several forms 

 of the same species, differing from each other in colour. 



^ For a fuller statement see Trans, yenner Institute (First Series), pp. 7-32. 



