27B 



BACILLI PATHOGENIC IN MAN. 



broader ; like these they are often slightly curved. One 

 can almost always observe in stained preparations that 

 the individual bacilli are composed of dark and clear 

 zones, so that under a low power they may resemble a 

 chain of cocci; but when higher powers are employed 

 this impression is seen to be incorrect. The clear un- 

 stained spaces are probably spores. The bacilli lie in 

 part singly, in part they are united in bundles of 4 to 

 8 parallel rods, in part they lie in confused masses. 

 It is by no means easy to stain these organisms well in 

 sections ; the glanders bacilli take up the aniline stains 



Fig. 80. Glanders bacilli. 



a, section from a glanders nodule X 700. 



b, bacilli of glanders stained with methylene blue X 1,500. 



with some difficulty, and further the dense accumulation 

 of strongly staining nuclei in the glanders nodules 

 renders the discovery of the bacilli difficult. The best 

 plan is to stain with alkaline methylene blue for 12 

 to 24 hours, then to treat the specimen cautiously 

 with very dilute acetic acid till the decolourisation has 

 so far advanced that the bacilli can be distinctly seen. 

 After such treatment we find, here and there, clearer 

 parts in the tissue where the masses of glanders bacilli 

 can be seen particularly sharply denned. 



The best situation for finding the bacilli are fresh 

 nodules which have not yet ulcerated ; in old ulcers, in 

 pus, in the secretions of the nose, &c., it is often impos- 

 sible to demonstrate bacilli, possibly because they have 

 passed into the spore stage. Weichselbaum has sue- 



