SPIROCHETES 327 



or a few granules, but no division into segments. It is 

 Gram-negative. Flagella have been noted. 



Spirochaeta Vincenti Is a delicate spiral-shaped 

 organism, said to be often found in the mouth as a simple 

 saprophyte. It was described by Vincent in 1896, in an 

 inflammatory lesion of the pharynx, since spoken of as 

 Vincent's angina, in association with a fusiform bacillus 

 of large size (3 to 10 micra by 0-5 to o-8 micron). The 

 curvature of the spirochetes is irregular and the number 

 of curves variable. The relationship of these organisms to 

 the disease is still obscure. 



THE MICRO-ORGANISM OF SYPHILIS. 



This is variously called the Spirochaeta pallida of 

 Schaudinn and Hoffmann, the Treponema pallidum, and 

 the Microspironema pallidum. It was discovered by the 

 two observers named in 1905, in the primary sore and 

 in the adjacent lymphatic glands. It has since been 

 demonstrated in numerous lesions and in the blood, and 

 in congenital syphilis. It has been found in large 

 numbers and in pure culture in the lungs, liver, spleen, 

 pancreas, and kidneys ; and in a few cases in the heart 

 muscle. It has also been found in the roseolar spots in 

 the disease, and in blister fluid in an infected person. 

 This shows how the disease can be spread (as at times 

 it has been) by vaccine fluid. 



In the bubo, other spirochaetes are usually found in 

 association with the Spirochaeta pallida. These are 

 much thicker, less undulated, more retractile, and more 

 deeply staining. They are spoken of as Spirochaeta 

 refringens. These are said to have an undulating membrane 

 (like the trypanosomes) but no flagella. The term 

 treponema is now reserved for a genus with no undulating 

 membrane, and flagella of some sort at their extremities. 

 To this group the organism of syphilis belongs, and is 

 hence now referred to more strictly as the Treponema 

 pallidum. 



The Treponema pallidum is an extremely delicate 

 spiral organism, very slender, about 6 to 14 micra long by 

 less than 0-5 micron thick, showing about a dozen very 



