MYCOBACTERIUM LACTICOLA a PLANUS. 429 



blooded animals ; but we may hope that the study of these 

 latter will some time disclose to us much which now is 

 dark in the matter of tuberculosis. 



In connection with Dr. Kumulis we have studied all the 

 representatives of this group which we could obtain; in all, 

 thirteen cultures. By detailed systematic comparison 

 they arrange themselves into two varieties, of which one 

 shows two or three forms. 



Rabinowitsch has pronounced her organism (Myc. lac- 

 ticola) identical with Myc. phlei. We find certain rather 

 important differences, so that we believe for the present 

 two species should be made. Lubarsch's observations, 

 which we received after our own were entirely concluded, 

 correspond in general very well with ours. The patho- 

 genic properties are so similar that they may be treated 

 together. 



Mycobacterium lacticola a planus. L. and N. 



(Plate 64.) 



Synonyms. — Organisms resembling tubercle bacillus 

 (Tuberculoseahnlicher) of Rubner-Obermiiller, grass or- 

 ganism II of Moeller i (C. B. xxv, 369). 



Microscopic Appearance. — Irregularly formed, 

 shorter and longer rods of exceedingly variable length, 

 straight or bent, partly acutely bent, often with clubbed 

 swellings; generally in older cultures they are rather thick 

 and often grown into threads of very irregular form. 

 Branching is present (64, x; 63, vi, xii a and h). 



They are not motile, and stain with methylene-blue, 

 ordinary fuchsin, by Gram's method, and exactly like the 

 true T. B. by the method for tubercle bacilli. ^ Growth 

 occurs upon all nutrient media, taking place slowly at 

 room temperature and somewhat more rapidly at incuba- 

 tor temperature, but always perceptibly faster than the 

 T. B. Oxygen is indispensable. In agar shake cultures 

 there is exceedingly little or no growth deep in the tube. 



1 According to our observations, Moeller's grass organism II is the 

 Myc. phlei. 



2 In smear preparations the staining property is lessened by agents 

 employed in removing fat. 



