208 BACTERIA. 



project beyond the straight outline of the bacillus ; sometimes 

 this is so much the case and the spores are packed so closely 

 together, that when examined under a sufficiently high power 

 the spore'bearing thread has been described as a chain of 

 cocci ; by some it is maintained that this appearance is 

 present only if the specimen is imperfectly stained, too much 

 heated, or too long treated with a strong acid ; whilst, on the 

 other hand, certain observers assert that the tubercle bacilli 

 also occur in the form of regular chains of cocci. The bacillus 

 is non-motile. 



Fliigge holds, however, that it is " always possible, in carefully 

 prepared specimens and with the aid of good lenses, to convince one's self 

 that the supposed chain of cocci does not exist, but that the delicate 

 contour of the bacillus can be for the most part traced through its whole 

 length, and that it is only within this contour that the alternation of stained 

 and unstained zones gives the deceptive appearance of stained cocci 

 separated by narrow intermittent spaces." 



The association of this organism with tubercular disease is 

 undoubted ; it is found in the lungs and sputum in various 

 forms of consumption, it is found also in tubercular ulcers 

 of the intestine, around the vessels in tubercular inflamma- 

 tion of the membranes of the brain, a condition which 

 occurs frequently in children, in tubercle of the liver and 

 of all other organs of the body, and in tubercular eruptions 

 of the skin such as lupus. In all these cases the bacilli are 

 found most abundantly at those points where the disease 

 appears to be spreading into the surroiinding tissues, and 

 especially where there is the formation of large multi- 

 nucleated epithelioid cells. If these bacilli are present 

 in considerable numbers in such an area, there will 

 usually be found in the immediate neighbourhood a small 

 portion of tissue that has undergone marked degenerative 

 changes, the cell protoplasm is somewhat hyaline or glassy 

 looking, and takes on any staining reagent, except perhaps 

 picric acid, very badly ; the nucleus i^ also considerably 

 altered, especially in that it no longer stains, or is stained 

 very imperfectly, with carmine or the aniline dyes. At such 

 a stage there can frequently be demonstrated, in these cells, 

 imperfectly stained tubercle bacilli, though in some cases 

 the bacilli stand out sharply and very brilliantly from 

 the glassy or homogeneous looking cell. After a time 

 the cells lose their outlines; they become more and more 



