ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 659 



of them were more or less hollow and were found to consist of a densely 

 interwoven mass of filaments, principally Schizothrix fasciculata Gomont. 

 Others from the banks of the Mississippi contained a species of 

 Scytonema. 



Schizomycetes. 



Bacillus of Epidemic Dysentery.* — L. Vaillard and Ch. Dopter 

 had the opportunity of observing this disease during the Vincennes 

 epidemic of last year. They were able to isolate by means of agar plate 

 cultures, from the stools of all typical and recent cases, the bacillus first 

 described by Chantemesse and Widal and afterwards by Shiga and 

 others. This bacillus is a short rod 1-3 /j. in length, non-motile, with- 

 out cilia and not forming spores. It stains with the ordinary anilin 

 dyes but not with Gram. It grows on ordinary media and does not 

 liquefy gelatin. It is distinguishable from B. coli by not forming 

 indol, by not acting on sugars with gas formation, and by not coagulat- 

 ing milk, and from B. typhosus by the absence of cilia and movement. 

 Cultures of it were agglutinated by the sera, in dilutions of £$ - g^, of 

 patients suffering, or having recently suffered, from the disease. This 

 agglutinating power appeared about the end of the first week of the 

 disease. Such sera did not agglutinate B. typhosus, but occasionally 

 did B. coli. There was no agglutination with the sera of healthv 

 persons or of those affected with tropical (amoabic) dysentery. The 

 authors were able, by subcutaneous injection, to produce experimentally 

 the disease in animals, notably in the cat and dog, and the lesions found 

 appeared identical with those of epidemic dysentery in man. The 

 bacilli were found in great numbers in the lesions of the intestinal tract. 

 The bacillus did not appear to secrete a soluble toxin, and injections of 

 filtered cultures did not produce appreciable effects. If, however, an 

 aqueous maceration of dead cultures was made and allowed to sediment, 

 injections of the supernatant bacilli-free fluid produced effects apparently 

 identical with those produced by injections of living cultures. The 

 authors maintain that the immunisation of animals is possible and 

 practicable from the point of view of serum-therapy. 



Nitrogen-assimilating Bacteria.f — Ed. v. Freudenreich worked 

 with the aerobic Azotobacter chroococcum (Beijerinck) and the anaerobic 

 Clostridium pastorianum ("Wmogradsky), but chiefly with the former. 

 This he describes as cocci with a diameter of 2-5 /x, elliptical forms 

 however being not uncommon, measuring 2-3 /j. by 3-6 /x. Three or 

 more refractile granules are to be seen in the cell protoplasm in un- 

 stained preparations. At times it seems to be motile. It can be 

 obtained by inoculating with earth a. solution containing, in water, 

 • 05 p.c. potassium biphosphate and 2 p.c. mannite. In this it grows 

 rapidly and from the pellicle formed on the surface it can be isolated by 

 making a series of surface cultures on agar having a similar composition. 

 It does not grow on potatoes, and bouillon inoculated with it remains 

 sterile, so that this medium may be used as a test of the purity of the 



* Ann. Inst. Pasteur, xvii. No. 7 (1903) pp. 463-91. 

 t Centralbl. Bakt., 2" Abt., x. (1903) pp. 514-22. 



LS 



