THE HIGHER BACTERIA 623 



the central filaments have approximately the thickness of an anthrax 

 bacillus and are, according to Babes,' composed of a sheath within 

 which the protoplasm contains numerous and different sized granules. 



About the periphery of the granules the free ends of the filaments 

 become gradually thickened to form the so-called actinomycosis " clubs." 

 These clubs, according to most observers, must be regarded as hyaline 

 thickenings of the sheaths of the threads and are believed to represent a 

 form of degeneration and not, as some of the earlier observers believed, 

 organs of reproduction. They are homogeneous, and in the smaller and 

 presumably younger granules are extremely fragile and soluble in water. 

 In older lesions, especially in those of cattle, the clubs are more re- 

 sistant and less easily destroyed. 



They appear only in the parasites taken from active lesions in animals 

 or man, or, as Wright ^ has found, from cultures to which animal serum 

 or whole blood has been added. In cultures from media to which no 

 animal fluids have been added, such as glucose agar or gelatin, no clubs 

 are found. In preparations stained by Gram's method the clubs give 

 up the gentian-violet and take counter-stains, such as eosin. 



The coccus-like bodies found occasionally lying between the filaments 

 of the central mass, most observers now agree, do not represent any- 

 thing comparable to the spores of the true hyphomycetes. In many 

 cases they are unquestionably contaminating cocci; in others again 

 they may represent the results of degeneration of the threads. 



In tissue sections, the microorganisms may be demonstrated by 

 Gram's method of staining or by a special method devised by Mallory.' 

 This is as follows for paraffin sections : 



1. Stain in saturated aqueous eosin 10 minutes. 



2. Wash in water. 



3. Anilin gentian- violet, 5 minutes. 



4. Wash with normal salt solution. 



5. Gram's iodin solution 1 minute. 



6. Wash in water and blot. 



7. Cover with anilin oil until section is clear. 



8. Xylol, several changes. 



9. Mount in balsam. 



Cultivation. — The isolation of actinomyces from lesions may be 

 easy or difficult according to whether the pus is free from contamination 



^ Babes, Virch. Arch., 105, 1886. 



'J. H. Wright, Jour. Med. Res., viii, 1905. 



' Mallory, Method No. 1, Malloiy and Wright, " Path. Technique," Phila,, 1908. 



