526 HILDA HEMPL HELLER 



extreme tip of cells, forming typical drumsticks. 3. Clostridium, 

 spores not produced at extreme tip of cells, at least not forming 

 drumsticks. Cells usually somewhat swollen when spores are 

 formed. 4. Metabacterium, with usually a number of spores 

 within a swollen cell. Tribe 2. Bacteriaceae, not producing 

 endospores. 



Rahn (1920) defines the anaerobes as sporulating rods that 

 store up logen (granulose) with or without glycogen. He 

 believes that further research would show the possibility of 

 changing any spore-forming anaerobe into another. 



THE CHARACTERS USED FOR CLASSIFICATION 



Let us consider the value in classification of the characters 

 whose use has been proposed in the above arrangements. 



Morphology of the vegetative cell. Most of the authors define 

 the Bacillaceae as rods. , Exceptions to this rule are the arrange- 

 ments of Zopf (1885) who believed in the transformation of 

 bacterial species, and of Jensen (1909), who used physiological 

 characters for his classification. Both Zopf and Jensen state 

 that spherical forms may be included in such a family. Appar- 

 ently the unity of origin of the cocci has never been settled by 

 systematists. Winslow and Winslow say (1908): ''Yet a con- 

 sideration of the properties of the members of the group makes 

 it clear that they are mutually interrelated and all sharply 

 separated from the rod-shaped bacteria, except perhaps at one 

 end of the series which they form." Breed, Conn, and Baker 

 do not consider the question of the unity of the origin of all 

 spherical bacteria as settled. The series of strains which Winslow 

 and Winslow used for their study did not, I believe, include any 

 strict anaerobes. Many cocci are facultatively anaerobic. 

 Strict anaerobes of this group are only occasionally met with, 

 but it does not follow that their occurrence is very rare, because 

 the usual technique for the isolation of anaerobes involves some 

 heating process that eliminates the non-spbrulating organisms. 

 Anaerobic cocci have been described by a number of authors. 

 Ozaki reviewed the subject (1915). There are, in his list, four 



