ACTINOMYCETES 431 



tissues of the fowl resemble quite closely those of the bovine 

 and human varieties in their size and general morphology. 

 The average length of a large number of measurements was 

 2.7 microns. Moore also tested the pathogenesis of the 

 freshly isolated avian tubercle bacteria on fowls, rabbits, 

 guinea-pigs, and pigeons. The results of these inocula- 

 tions, however, were unsatisfactory, as were also feeding 

 experiments of healthy fowls with human tuberculous 

 sputum rich in bacteria. 



Pseudotuberculosis. — Anatomical lesions very suggestive 

 of, though not identical with, those produced by bacillus 

 tuberculosis, have also from time to time been observed in 

 mice, rats, guinea-pigs, rabbits, cats, goats, bovines, hogs, 

 and man. They do not appear to be of a specific nature as 

 regards etiology, for the reason that different authors have 

 described different organisms as the causative agents. 

 These affections are usually classed under the name pseudo- 

 tuberculosis. 



ACTINOMYCETES. 



The term actinomycetes is restricted to a group of organ- 

 isms having morphological affinities with the bacteria on 

 the one hand and the hyphomycetes on the other. They 

 resemble the bacteria in that they occur as homogeneous 

 threads which under artificial cultivation may become 

 segmented into short bacillus- or coccus-like fragments. 

 'Furthermore, they are unlike the molds in that they have 

 not a double wall; are not filled with fluid containing gran- 

 ules, and the segments are not separated from one another 

 by a distinct partition. They simulate the molds in that 

 they develop from spores into dichotomously branching 

 threads, which ultimately form colonies having more or 



