290 



ACTINOMYCOSIS AND ALLIED DISEASES. 



probable that some of the spherical bodies formed within fila- 

 ments when growing in the tissues have the same significance, 

 i.e. are gonidia, whilst others may be merely the result of de- 

 generative change. Some observers have described young 

 colonies largely composed of spherical forms, as if these multi- 

 plied by division, but this latter point is still doubtful. Both 

 the filaments and the spherical bodies are readily stained by 

 Gram's method. 



<"+ 





ft 



X^j*~: .Y^ 



,\*-'sv4s s iv-* :#. 



-r^r^^iifi' & 



FlG. 102. Actinomyces in human kidney, showing clubs radially arranged and sur- 

 rounded by pus. The filaments had practically disappeared. 



Paraffin section ; stained with haematoxylin and rubin. X 500. 



3. Clubs. These are elongated pear-shaped bodies which 

 are seen at the periphery of the colony, and are formed by a 

 sort of hyaline swelling of the sheath around the free extremity 

 of a filament (Figs. 102, 103). They are usually homogeneous 

 and structureless in appearance. In the human subject the 

 clubs are often comparatively fragile structures which are easily 

 broken down and may sometimes be dissolved in water. Some- 

 times they are well seen when examined in the fresh condition, 

 but in hardened specimens are no longer distinguishable. In 

 specimens stained by Gram's method they are not coloured by 

 the violet, but take readily a contrast stain, such as picric acid, 

 rubin, etc. ; sometimes a darkly-stained filajnent can be seen 



