378 DIVISION III. MODE OF LIFE OF THE FUNGI. 



which we must not describe at greater length in this place, Actinomyces forms yellow 

 bodies like sand-grains about i mm. in diameter. The larger of these bodies, which 

 are visible to the naked eye, always consist of a number of single growths of 

 Aclinomyces united into a mass by the soft swollen tissue. 



Each Actinomyces may be best described as a round or less commonly 

 elongated hollow body sometimes pressed flat with a relatively thick wall and narrow 

 cavity. The wall looks like a dense hymenomycetous or discomycetous hymenium 

 with very slender elements, being composed of filaments which are copiously branched 

 and have their branches at right angles to the surface and therefore radially disposed 

 when the form of the body is round, and are crowded close together and difficult to 

 separate from one another. Many of these crowded branches are club-shaped at their 

 outer extremity, and in this point again therefore may be compared with asci or narrow 

 hymenomycetous basidia ; some are constricted and torulose. They mostly end at a 

 uniform height in the smooth outer surface of the body, though single ones some- 

 times extend a long way beyond the rest according to the figures which are given (see 

 Ponfick, t. vi). 



The inner cavity of the body, which is surrounded by this kind of wall and as 

 was said is comparatively narrow, is filled with a dense tangled mass of slender much- 

 branched filaments, the branches of which are continuous with those of the wall. 

 Roundish or elongated grains of about the thickness of the filaments and not 

 unlike small spores are found between the filaments, at least in some specimens. 



The filaments appear to be filled with a homogeneous protoplasm, in which 

 single granules or perhaps vacuoles are rarely to be distinguished ; it is uncertain and 

 a disputed point whether they are septate. They attain at most a breadth of 2-3 /* in 

 the broadest parts of the club-like swellings which I could find, in other parts 

 scarcely a third of that measurement. 



The Actinomyces is sometimes incrusted with lime. 



The structure of Actinomyces certainly favours the view that it is of the nature of 

 a Fungus, but it has no closer resemblance than this to well-known Fungi. It is not 

 possible therefore to assign it a place in the system, or to form any clear idea of the 

 history of its growth and development from the analogy of other Fungi. Experiments 

 in its cultivation outside the body of the animal have yielded no results of importance 

 to our knowledge of its development. All that can be said about it is founded entirely 

 on the state of things observed in the creature attacked with actinomycosis either 

 living or dead. From the experiments of Ponfick and especially of Johne it would 

 seem possible that Actinomyces grows, because when fresh matter was introduced by 

 inoculation beneath the skin or in hollow places in the bodies of horned cattle, the 

 specific swellings containing Actinomyces were produced in them even in parts of the 

 body at a distance from the places where the inoculation was performed. That the 

 latter were a new growth and not the individuals introduced by the inoculation is 

 certainly not proved, but is not to be disputed ; at any rate there can be no doubt that 

 actinomycosis is produced by inoculating with Actinomyces. We can frame concep- 

 tions of our own as to how growth is eventually brought about, but none of them rest 

 on a secure foundation. 



The same writers found often in fresh material the club-shaped elements of the 

 wall-layer separated from one another, and a large number of club-shaped sprouts 



