MORPHOLOGY AND STAINING PROPERTIES 255 



The disease generally takes an acute, and, as a rule, fatal course. 

 On postmortem examination the cadaver is generally much distended, 

 not merely at the abdomen but over the entire external surface 

 which is filled with gas. The formation of the latter continues after 

 death. The subcutaneous tissue upon removal of the skin presents 

 a gelatinous, yellowish or hemorrhagic appearance; the muscles 

 appear dark, red brown or black brown. The soft, necrotic muscles 

 crepitate and discharge gas on section. They are sometimes so full 

 of air that they float on water like a piece of lung. The meat of 

 animals dead from black-leg has a peculiar sweetish, rancid, non- 

 fetid smell. Sometimes only one extremity shows these characteristic 

 changes, at other times two, three, or all four are involved. While 

 the parts affected by the disease always contain an enormous quantity 

 of blood, the unaffected parts may be very pale and anemic. 1 In 

 addition to these changes hemor- 

 rhages into the serous membranes FIG. 135 

 and an accumulation of hemor- 

 rhagic serous fluid in the various 

 body cavities are found. The 

 liver and kidneys show evidences 

 of parenchymatous degeneration; 

 the former is sometimes filled with 

 gas (foamy liver). The specific 

 bacilli are found in the diseased 

 muscles, serous hemorrhagic exu- 

 dates, and gall-bladder, liver, etc. 

 Many of the organisms are gener- 

 ally sporulating. 



Morphology and Staining Proper- 

 ties. The bacillus Of emphy- Bacilli of symp tomatic anthrax, showing 



sematous anthrax is from 2 to 6 spores. (After Zettnow.) 



micra long and 0.5 to 0.8 micron 



wide. It generally appears singly, or in pairs, rarely in long chains; 

 some are cylindrical, others more oval (hence the name, clostridium), 

 still others are club-shaped. French authors have compared the shape 

 of the bacillus to snow-shoes. The clostridium shape is best seen 

 after sporulation has taken place. The organism, unlike the anthrax 

 bacillus, forms spores while in the body of the live animal. The 

 spores are generally in the middle of the bacterium, sometimes more 

 toward one end, and many of them, particularly in cultures, are 

 found free. In young cultures the bacilli are quite actively motile 

 and possess numerous flagella, which, however, break off easily and are 

 generally difficult to demonstrate by staining methods. The bacillus 

 stains in a peculiar manner with iodin solution. The vegetative 



1 A condition like this where an anemia of one part is brought about by a congestion in another 

 part is called a collateral anemia. 



