210 



TUBERCULOSIS. 



in the tissues. They are straight or slightly curved, and 

 appear of uniform thickness, and, when stained, are 

 uniformly coloured, or may present small uncoloured 

 spots along their course, with darkly-stained parts between. 

 In the case of the tubercle bacillus, as of many other 

 organisms, a considerable amount of discussion has 

 taken place as to the occurrence of spores. In such a 

 minute organism it is extremely difficult to recognise the 

 exact characters of the unstained points. Accordingly, we 

 find that some consider these to be of the nature of spores, 

 while others find that it is impossible to stain them by any 

 means whatever, and consider that they are really of the 

 nature of vacuoles. Others again hold that some of the 

 condensed and highly-staining particles are of the nature 

 of spores. It is impossible to speak dogmatically on the 

 question at present. We can only say that the younger 

 bacilli stain uniformly, and that in the older forms this 

 inequality in staining is met with, but it has not been defi- 

 nitely proved that this always indicates spore formation. 



Bacilli with their pro- 

 toplasm thus broken 

 up often appear like 

 short rows of cocci. 



The bacilli in the 

 tissues occur scattered 

 irregularly or in little 

 masses. They are 

 usually single, or two 

 are attached end to 

 end, and often form 

 in such a case an 

 obtuse angle. True 

 chains are not formed, 

 phthisical but occasionally short 

 filaments are met 

 with. In cultures the 

 bacilli form masses 

 in which the rods are closely applied to one another and 



FIG. 57. Tubercle bacilli 

 sputum. 



Film preparation, stained with carbol- 

 fuchsin and methylene-blue. x 1000. 



