210 THE INFECTIOUS DISEASES. 



does in many cases, both the local and general phenomena of diphtheria, 

 this disorder has formerly been confounded with it, and has been only 

 recently recognized as a distinct phase of disease. It is now most fre- 

 quently called pseudo-diphtheria. It seems in part to cover the condi- 

 tion formerly known as croup, in part those cases formerly thought to be 

 mild diphtheria. In many phases of acute angina, and in many cases of 

 follicular tonsillitis, streptococci have been found in large numbers. 

 Other bacteria, either alone or in association with the pyogenic cocci, 

 may be excitants of pseudo-membranous as well as simple angina. 



OTHER BACTERIA WHICH ARE FREQUENT EXCITANTS OF 

 SUPPURATION. 



While the Staphylococcus pyogenes and Streptococcus pyogenes are 

 the most common excitants of local suppuration with and without toxaemia 

 and septicaemia, such conditions, as we have seen, are not infrequently due 

 to other micro-organisms. Among these we may mention here as the 

 more common and important : Micrococcus lanceolatus, the gonococcus, 

 Micrococcus'tetragenus, Bacillus pyocyaneus, the colon and the typhoid 

 bacillus, the bacillus of glanders, the tubercle bacillus, the pueumo- 

 bacillus of Friedlauder, the diplococcus of cerebro-spinal meningitis, 

 Bacillus pyogeues fostidus, and Actinomyces with its related forms. 



In some of these organisms the pyogeuic qualities in their relation- 

 ships to human infections are most conspicuous ; in others, the reaction 

 of the body to their presence is such as to justify a special name. The 

 latter is particularly noteworthy in the case of the pneumococcus, the 

 gonococcus, glanders, typhoid, and tubercle bacilli, diplococcus meniu- 

 gitidis, and actinomyces. 



Many other micro-organisms may be excitants of suppurative inflam- 

 mation in man as well as in the lower animals under experimental 

 conditions, but this exceptional reaction of living tissues does not fall 

 within the scope of this work, which deals primarily with such tissue re- 

 actions as may occur under the natural conditions of life. 



THE BACILLUS COLI COMMUNIS AND THE COLON GROUP. 



The bacillus coli communis is an organism so frequently present in the 

 intestines under normal conditions as to be commonly called the " colon 

 bacillus." It is motile, facultative aerobic, asporogenous, considerably 

 resembling in general form the typhoid bacillus (see p. 227). It has 

 been repeatedly found under such conditions in connection with suppura- 

 tive processes as to justify the belief that it is often their excitant, 



It has been found in various forms of peritoneal suppuration, both 

 with and without such lesions of the intestine as would obviously permit 

 of its egress; in appendicitis ; in suppuration about the gall-ducts ; inhrem- 

 orrhagic pancreatitis ; in inflammatory processes in the genito-urinary 

 apparatus ; in the pericardium and pleura. Although a usual inhabitant 

 of the intestinal canal, the Bacillus coli is often extremely virulent when 



