340 SA CTERIOL OGY. 



misnomer, and that it would be more nearly correct to 

 designate this organism as the attenuated or non-viru- 

 lent diphtheritic bacillus, reserving the term ''pseudo- 

 diphtheritic" for that organism or group of organisms 

 (for there are probably several) that is enough like the 

 diphtheria bacillus to attract attention, but is distin- 

 guishable from it by certain morphological and cultural 

 peculiarities aside from the question of virulence. 



It is a well-known fact that many pathogenic organ- 

 isms — conspicuous among these being the micrococcus 

 lanceolatus, the staphylococcus pyogenes aureus, and the 

 group of so-called "hemorrhagic septicaemia" organ- 

 isms — undergo marked variations in the degree of their 

 pathogenic properties, and yet these organisms, when 

 found either devoid of this peculiarity, or possessing it 

 to a diminished degree, are not designated as ''pseudo " 

 forms, but simply as the organisms themselves, the viru- 

 lence of which, from various causes, has been modified. 



Note. — Prepare cover-slip preparations from the 

 mouth-cavities of healthy individuals and from those 

 having decayed teeth. Do they correspond in any way 

 with those made from diphtheria ? Do the same with 

 different forms of sore-throat. Do the peculiarities of 

 any of the organisms suggest those of the bacillus of 

 diphtheria? Wherein is the difference? 



In cultures and cover-slips made from both diph- 

 theria and from innocent sore-throats are there any 

 organisms which are almost constantly present ? Which 

 are they, and what are their characteristics ? 



Which are the predominating organisms in the an- 

 ginas of scarlet fever ? 



Do these organisms simulate, in their cultural and 



