RAY FUNGUS 2OI 



Cultures have been made on serum and glycerine agar, which, 

 though resembling the tubercle bacillus, are more delicate, and not 

 so luxuriant. To cultivate the leprosy bits of tissue are stripped 

 off and allowed to digest with trypsin on blood serum or agar 

 plates. When the tissue has softened and the bacilli multiplied, 

 transfers are made to serum glycerine media or those containing 

 tryptophan. It is best alkaline in reaction. The growth is moist 

 and pale yellow or later pink. It is aerobic. The more recently 

 isolated strains grow very slowly. Variations in the media produce 

 various grades of pigmentations. Apparently leprosy bacilli cannot 

 break up complex protein molecules. 



Pathogenesis. It is highly pathogenic for man and monkeys, 

 producing in the former a slow chronic disease, which is, probably, 

 transmitted by more or less intimate personal contact. The bacillus 

 is seen in enormous numbers in lepra cells and elsewhere in diseased 

 tissues and has been found in the blood. The lepra cells are large 

 and vacuolated, and literally crammed full to bursting with bacilli. 

 In general the leprous lesion resembles a tubercle, as it consists of 

 giant cells, epithelial, and round cells. 



Immunity. There is very little accurate knowlege as to immu- 

 nity against this organism; of late bacterins have been tried with 

 some success it is claimed. 



RAY FUNGUS. 



Actinomyces Bovis. 



Ray Fungus. 



Morphology and Stains. This organism is called the ray fungus 

 because of the stellate arrangement of its threads in the colonies 

 found in tissues. It is of a more complex structure than the bac- 

 teria hitherto described. There are three elements found in every 

 colony: i. Long thread which may be branched or unbranched. 



2. Threads that are clubbed, which may, or may not, be branched. 



3. Spore-like bodies contained within the thread, from the ends of 



