200 GONORRHOEA, SOFT SORE, SYPHILIS. 



Microscopical Characters. This organism occurs in the 

 form of minute oval rods measuring about 1.5 ^ in length, 

 and .5 p. in thickness. It is found mixed with other 

 organisms in the purulent discharge from the surface, and 

 is chiefly arranged in small groups or in short chains. 

 When studied in sections through the ulcer it is found in 

 the superficial part of the floor, but more deeply situated 

 than other organisms, and may be present in a state of 

 purity amongst the leucocytic infiltration. In this position 

 it is usually arranged in chains which may be of consider- 

 able length, and which are often seen lying in parallel 

 rows between the cells. Both in the tissues and in the 

 secretions the bacilli chiefly occur in the free condition, 

 but occasionally a few may be contained within leucocytes. 



This bacillus takes up the basic aniline stains fairly 

 readily, but loses the colour very rapidly when a decolor- 

 ising agent is applied. Accordingly, in film preparations 

 when dehydration is not required, it can be readily stained 

 by most of the ordinary combinations, though Loffier's or 

 Kiihne's methylene-blue solutions are preferable, as they 

 do not overstain. In sections, however, great care must 

 be taken in the process of dehydration, and the aniline-oil 

 method (vide p. 107) should be used for this purpose, as 

 alcohol decolorises the organism very readily. A little of 

 the methylene-blue or other stain may be with advantage 

 added to the aniline oil used for dehydrating. 



This organism has not yet been successfully cultivated 

 outside the body, though practically every medium has 

 been tried for this purpose. Ducrey, however, succeeded 

 in separating it from other organisms by the following 

 method. He produced a series of pustules by successive 

 inoculations in the human subject on the skin, which had 

 been previously sterilised, the pustules being afterwards 

 protected from contamination by watch-glasses fixed in 

 position. He found that in this method the other organisms 

 gradually died off, while the characteristic bacilli persisted 

 and at about the fifth or sixth inoculation might be present 

 alone. Further, the pus containing the bacilli in a pure 



