Distribution Morphology 661 



GASEOUS EDEMA. 



BACILLUS AEROGENES CAPSULATUS (WELCH). 



General Characteristics. A large, stout, non-motile, non-flagel- 

 lated, sporogenous, non-chromogenic, purely anaerobic, markedly aero- 

 genie, doubtfully pathogenic bacillus, easily cultivated in artificial 

 media, readily stained by the ordinary methods and by Gram's method. 



This disease is caused by an interesting micro-organism 

 described by Welch, and subsequently studied by Welch 

 and Nuttall,* Welch and Flexner,f and others. Welch said 

 at the meeting of the Society of American Bacteriologists held 

 at Philadelphia, December 30, 1 904, that he believed this or- 

 ganism to be identical with Kline's Bacillus enteritidis sporo- 

 genes, and that it belongs to the butyric acid group. It is 

 probably also identical with Bacillus phlegmone emphysema- 

 tose of Frankel.J It was first secured by Welch from the 

 body of a man dying suddenly of aortic aneurysm with a pe- 

 culiar gaseous emphysema of the subcutaneous tissues and in- 

 ternal organs, and a copious formation of gas in the blood- 

 vessels. The blood was thin and watery, of a lac color, and 

 contained many large and small gas bubbles, and many 

 bacilli, which were also obtained from it and the various 

 organs, especially in the neighborhood of the gas bubbles, 

 in nearly pure culture. The coloring-matter of the blood 

 was dissolved out of the corpuscles and stained the tissues 

 a deep red. 



Distribution. The organism is apparently of wide dis- 

 tribution. It is believed that the natural habitat of the 

 bacillus is the soil, but there is reason to think that it com- 

 monly occurs in the intestine, and may occasionally be found 

 upon the skin. 



Morphology. The bacillus is a large organism, measuring 

 3-5 fj. in length, about the thickness of the anthrax bacillus, 

 with ends slightly rounded, or, when joined, square (Fig. 

 1 99) . It occurs chiefly in pairs and in irregular groups, but 

 not in chains, in this particular differing from the anthrax 

 bacillus. In culture media it is usually straight, with slightly 

 rounded ends. In old cultures the rods may be slightly 

 bent, and involution forms occur. The bacillus varies some- 



* "Bull, of the Johns Hopkins Hospital," July and Aug., 1892, 

 vol. vin, No. 24. 



t "Jour, of Experimental Medicine," Jan., 1896, vol. I, No. 1, p. & 

 j "Centralbl. f. Bakt.," etc., 1893, Bd. xm, p. 13. 



