TUBERCULOSIS. 2OJ 



of the organism. The length is sometimes given at 2.6/* 

 and the breadth as from .2 to .5^. They are usually 

 described as from a quarter to a half the diameter of a red 

 blood corpuscle and longer than the bacilli of mouse septi- 

 caemia, or 0.0015 to 0.0035 m.m. in length. These bacilli 

 always appear to have the larger dimensions when treated 

 by Baumgarten's liquor potassae method. The bacilli are 



m 



Photo-micrograph of Sputum, from a phthisical patient, containing large 

 nucleated epithelial cells and characteristic tubercle bacilli, x xooo. 



usually slightly curved, or two are arranged end to end 

 so as to contain an angle. At first they were described as 

 not containing spores, but it was demonstrated by Watson 

 Cheyne that from two to six spores may frequently be seen 

 in these rods ; the spores occurring as small ovoid or rounded 

 clear spaces placed at intervals in the stained thread. In 

 some cases they are so prominent that they appear to 



