CULTURAL PROPERTIES 411 



small, round, cocci-like bodies. The latter are the spores. They are 

 not only found in the interior of the filaments, but also free between 

 them. These, however, unlike the spores of the simple, true bacteria, 

 have the same staining properties as the filaments, but they are more 

 resistant than the filaments (see below). In addition to the slender 

 well-stained filaments, there are seen coarse, poorly and irregularly 

 stained threads, which are provided with a coarser, more densely 

 stained membrane. Very pale threads containing stained round 

 bodies, only here and there, are also seen. These are filaments 

 in a well-advanced stage of degeneration. At the periphery of the 

 actinomyces granule the free ends of the filaments have formed clubs, 

 which are more or less round or more commonly elongated and truly 

 club- or pear-shaped. These club-shaped formations are due to a 

 gelatinous degeneration of the membrane of the coarser and less 

 uniformly stained filaments; the latter can often be seen at the inner 

 portion of the swollen club. The clubs are sometimes divided into 

 segments by one or more lines of partition, and the individual parts 

 forming them are often bulged out at the sides, so that the lines of 

 division appear as constricting rings. All these morphologic features 

 are due to degenerative changes of the membrane and of the inner proto- 

 plasmic thread of the filaments. The wall of the actinomyces granule 

 or rosette is deficient in one place where the filaments partially filling 

 the cavity project out of it into the surrounding pus or tissue. These 

 projecting masses of filaments have been called the root of the 

 actinomyces rosette. All of these features are well marked in com- 

 paratively young rosettes. When they grow older most of the details 

 disappear and often nothing is left but a rosette formed by the 

 degenerated gelatinous clubs. The best material for studying the finer 

 details of the structure of the actinomyces granules is a soft granulo- 

 matous tissue, not a hard, fibrous one, which generally contains older 

 actinomyces colonies which no longer show the finer details. 



Cultural Properties. All who have attempted to obtain actinomyces 

 in pure cultures agree that this is a difficult task. Actinomycotic 

 material must be obtained from the interior of a lesion in an aseptic 

 manner and then numerous culture tubes must be inoculated, because 

 in only a very small percentage will the fungus grow in a first gener- 

 ation. The material obtained is first rubbed up in a sterile mortar 

 with the addition of melted gelatin or bouillon and then again inocu- 

 lated into sterile melted gelatin tubes and their contents are finally 

 poured into Petri dishes. Some of these must be kept under aerobic 

 others under anaerobic conditions, because some varieties or species 

 of actinomyces are aerobic, others anaerobic. When a first generation 

 has once been obtained it is easy to secure the organism in a second 

 and in subsequent generations on gelatin, glycerin agar, blood serum, 

 potatoes, and in hen's and pigeon's eggs. On gelatin plates, if the 

 fungus grows in a first generation under aerobic conditions, a small, 

 gray point appears on the fifth or sixth day. Microscopic examination 



