ALTERATIONS IN THE FORM OF THE MOTHER-CELL 47 



When this happens at one of the polar terminations of a rod-shaped cell, the 

 latter then assumes the form of a nail or drumstick. Bacteria exhibiting this 

 peculiarity are styled nail-bacteria or helo -bacteria by Billroth, or Urocephalum 

 by Trecul ; and in medico-bacteriological literature they are also frequently 

 called pin-head bacteria. The earliest known example of this kind was the 

 Vibrio rugula (Fig. 15), frequently encountered in pools, and another is the 



FIG. 15. Vibro rugnla. FIG. 16. Clostridium butyricum. 



Seven rods, eacb with .1 ter- Spore formation. 



minal spore. (After Praz- w 6 pure , y vege tative cells ; d. commencement of spore 



formation ; c-e. progress ; f-h. completion ; -/. contain 

 granulose stained blue by iodine ; h. devoid of this car- 

 bohydrate, unstained by iodine ; g. cell with two spores. 

 (After Prazmowsln.) Magn. 1020. 



"drumstick bacillus," found in human faeces by BIENSTOCK (I.). The author 

 has often found morphologically similar fission fungi in the skin developing on 

 the surface of boiled infusions of hay ; and as a matter of general interest an 

 example from the pathogenic bacteria may be cited, viz., Bacillus tetani, by 

 which tetanus is produced. 



Not inferior in number are the species wherein the sporogenic rod ordinarily 

 swells up in the middle and gives rise to a spindle-shaped outline resembling 

 that of a lemon or cop of yarn. TKECUL (I.), 

 who in 1865, in the course of his studies in 

 butyric fermentation, first became acquainted 

 with this bacterial form, gave it the name of 

 Clostridium, a term adopted as a generic name 

 by Prazmowski. The two species described by 

 this worker, viz., Clostridium butyricum (Fig. 

 1 6) and Cl. Polymyxa, were supplemented by 

 LIBORIUS (I.) with Clostridium fatidum, a fission 

 fungus, which is isolated from old cheese, and 

 produces a repellent odour in artificial nutrient 

 media. A fourth species is the Bacillus alvei, 

 discovered by CHESHIBE and UHEYXE (I.), which 

 causes the so-called " foul brood " in bees. 

 The Bacilhis inflatus (Fig. 17), discovered by 

 ALFKED KOCH (I.) in 1888, also belongs hereto. 

 Beyerinck investigated the conditions under 

 which the Clostridium form is assumed by a 

 number of species, having close affinities with Clostridium butyricum, which 

 have been grouped under the genus Granulobacter. 



FIG. 17. Bacillus inflatus. 



Spore formation. 



a, b, e. cells of Clostridium form, each 

 containing 1 one elongated cylindrical 

 endospore ; c,d,f,ff. cells with two 

 spores of unequal size. (After A. 

 Koch.) Magn. 2100. 



