XIV] BACILLUS TUBERCULOSIS 355 



The subcultures on glycerine Agar show after several 

 months besides the typical forms of cylindrical and granular 

 tubercle bacilli also some filaments made up of rods and 

 granules. Some of these filaments are remarkable by their 

 being undoubtedly branched like the mycelium of a 

 hyphomycetes, and, further, that some are club-shaped at 

 the end or beaded in their course ; these club-shaped and 

 branched filaments (see Fig. 138) are the more numerous 

 the older the culture. Although the club-shaped and 

 beaded condition might correspond to involution of the 

 threads, the branched condition cannot, and therefore the 

 club-shaped forms may well represent the growing ends 

 of the threads of a mycelium ; the two together, i.e., club- 

 shaped and branched threads, would, therefore, indicate 

 that the typical tubercle bacillus is a phase only in the 

 development of an organism, which under certain conditions 

 (glycerine Agar) declares its true nature and origin, being, 

 namely, comparable to a fungus having a mycelial stage 

 {see Klein in the Reports of the Medical Officer of the 

 Local Government Board, 1889-90, Plate XXVIL, Figs. 

 61, 62, 63). 



Later, Mafucci {Archiv f. Hygiene und Infect., xi. p. 445) 

 described the same forms in the culture of the tubercle 

 bacilli of the fowl, and Fischel {Fortschr. d. Med., End. x. 

 No. 22, p. 908) also of the human tubercle cultures; and 

 this latter observer arrived at the same conclusion as 

 myself — viz. that we are dealing with forms which are 

 comparable to a mycelial fungus. 



That the tubercle bacilli in one phase or another do 

 contain spores has been shown by Koch, who found that 

 tubercular sputum when thoroughly dried maintains its 

 virulent character, This has been confirmed by other 

 observers. 



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