MICROSCOPIC AND CULTURAL CHARACTERS. 399 



tion of the poison. From the ham in question, which was not 

 decomposed in the ordinary sense, Van Ermengem obtained 

 numerous colonies of this bacillus, the leading characters of 

 which are given below. It may be added that Romer obtained 

 practically the same results as Van Ermengem in a similar con- 

 dition, and that the bacillus botulinus has been cultivated by 

 Kemper from the intestine of the pig. 



Microscopical and Cultural Characters The organism is a 



bacillus of considerable size, measuring 4 to 9 /u. in length and 

 .9 to 1.2 jn in thickness; it has somewhat rounded ends and some- 

 times is seen in a spindle form. It is often arranged in pairs, 

 sometimes in short threads. Under certain conditions it forms 

 spores which are oval in shape, usually terminal in position, and 

 a little thicker than the bacilli. It is a motile organism and has 

 4 to 8 lateral flagella of wavy form. It stains readily with the 

 ordinary dyes, and also retains the colour in Gram's method, 

 though care must be employed in decolorising. 



The organism can be readily cultivated on the ordinary media, 

 but only under strictly anaerobic conditions. In glucose gelatin 

 a whitish line of growth forms with lateral offshoots, but lique- 

 faction with abundant gas formation soon occurs. In gelatin 

 plates the colonies after four to six days are somewhat charac- 

 teristic ; they appear to the naked eye as small semi-transparent 

 spheres, and these on examination under a low power of the 

 microscope have a yellowish-brown colour and are seen to be 

 composed of granules which show a streaming movement, 

 especially at the periphery. Cultures in glucose agar resemble 

 those of certain other anaerobes ; there is abundant development 

 of gas, and the medium is split up in various directions. The 

 cultures have a rancid, though not foul, odour, due chiefly to 

 the development of butyric acid. The optimum temperature is 

 below that of the body, viz., between 20° and 30° C. ; at the 

 body temperature growth is slower and less abundant aijd spore 

 formation does not occur. 



Pathogenic Effects. — Like the tetanus bacillus, the bacillus 

 botulinus has little power of flourishing in the tissues, whereas 

 it produces a very powerful toxin. Van Ermengem found that 

 the characteristic symptoms could be produced in certain ani- 

 mals by administering watery extracts of the infected ham or 

 cultures either by the alimentary canal or by subcutaneous 



