ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 419 



group, from the lesions of infective jaundice. The organisms appeared 

 in the liver, blood, freces and urine. The bacilli generally appear as 

 long, granular, incurved filaments — particularly so in the muscular 

 lesions^ small liver abscesses, myocardium and lungs of experimentally 

 infected rabbits. The microbe grows best in calf- or ox-liver broth. 

 In these media refractile ovoid thickenings can be seen, two or three in 

 number, and apparently isolated in the bodies of the organisms. The 

 bacilli stain best with carbol-fucbsin, the granules taking the stain 

 better than the rest of the cell-substance, so that the stained organism 

 has a somewhat striated appearance. The shorter forms show bipolar 

 staining. All forms stain indifferently with methylene-blue and carbol- 

 thionin, and the granules do not stain with Sudan 111, iodine, or 

 Neisser's stain. Bacillus icteriijens does not form chains, is non-acid- 

 fast, and is quite Gram-negative. The short forms exhibit slight 

 oscillating movements (Brownian movement), but are, however, non- 

 motile. "The enumeration of these characters of the B. kterigens, 

 added to the odour of its cultures, appears perhaps sufficient to authorize 

 its inclusion in the group of the Actinomycetes." 



Morphology of Bacteria in Leaf Nodules of Pavetta cofFra.* — ■ 

 P. Georgevitch has isolated two different species of bacteria from the 

 leaf nodules of Pavetta coffra (natural order Ruliacea). One of the 

 species, which he calls a, is very motile, forms spores, and does not 

 branch ; the other species {(T) does not form spores, is non-motile, and 

 splits up on artificial media into a numl^er of particles (arthospores) 

 which continue to grow and branch by budding. The bacterium j8 

 forms a rod 3 to 5 yu. in length and of 1 /a in thickness ; it is irregular 

 in transverse section, and is slightly curved. It grows well on potato at 

 ?)?," C, and forms pale yellow colonies upon agar, on which medium the 

 bacillus a forms milky white opalescent colonies. Bodies containing 

 chromatic granules (arthospores) are formed by the bacillus /S l)y means 

 of a process of segmentation, and are capable of development upon 

 suitable media. They lose their round form and become oval, and two 

 chromatic granules appear on opposite sides of the arthospore, which 

 becomes divided into two equal portions by means of a transverse 

 septum. The arthospore becomes more and more elongated, more 

 septa are formed, the lateral walls invaginate in the neighbourhood of 

 .the septa, and the cell breaks up into a new series of arthospores. 



* C.R. Soc. Biol. Paris, Ixxix. (1916) pp. 411-3. 



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