5 0. Clostridiutn 



Thirty-one species of Clostridium were studied with two or 

 more strains of each species. The cultures were suppHed by Dr. 

 L. S. McCking of Indiana University. In agreement with the 

 Hterature the only definitely nonflagellated and nonmotile species 

 was Clostridium perfringens, of which five strains were studied. 

 The single strain of Clostridium nigrificans studied did not show 

 an)' flagella but the growth was not entirely satisfactory and much 

 significance should not be attached to this finding. 



Flagellar Characteristics 



All the motile strains studied showed peritrichous flagellation. 

 With a few exceptions the flagella stained readily. Some species of 

 Clostridium grow with difficulty in media without particulate mat- 

 ter and had to be cultured in thiogly collate medium (O.l^r agar), 

 corn mash, etc., which made washing not entirely satisfactory. 

 The flagella of three species stained with more difficulty than 

 those of the other species. These were Clostridium felsineum, C. 

 acetohutijlicum, and C. roseum. C. acetobutijlicum and C. roseum 

 are very similar morphologically. Strain McClung 638 of C. fel- 

 sineum showed normal flagella only but strain 639 showed flagella 

 much like C. acetohutijlicum with a mixture of flagella of short 

 and long wavelength. This species requires further study but 

 morphologically it appears very similar to C. acetohutijlicum and 

 C. roseum. The flagellation of Clostridium tetani deserves special 

 mention. Two strains were studied and, while one was better 

 flagellated than the other, both showed the same type of flagella 

 which were rather stiff with relatively short wavelength and large 

 amplitude. The same type of flagella, with longer wavelength, 

 was also found in the strains of Clostridium noviji studied. This 

 flagellation, if similar in all strains, is so distinctive as to be diag- 

 nostic. 



In some species of Clostridium only normal flagella were ob- 

 served, in other species the flagellation was predominantly normal 

 with an occasional curly flagellum mixed in with the normal. 

 Several species showed both normal and curly flagellated indi- 

 viduals. Coiled flagella were particularly prominent in the aceto- 



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