DESCRIPTION OF PLATES XX. AND XXI. 

 Actinomycosis Bovis. 



PLATE XX. 



Fig. 1. — From a section of an actinomycotic tongue stained by tile triple 

 method (Ziebl-Neelsen, logwood and orange-rubin). In this section the 

 separate centres of growth are clearly shown. Each neoplasm consists of 

 a fungus system, in which the masses of the fungus, situated more or less 

 centrally, are surrounded with round cells, epithelioid cells, sometimes 

 giant cells, and lastly fibrous tissue forming a more or less distinct 

 capsule. In parts the fungi have fallen out of the section. x 50. 



Fig. 2. — From a section of a "tubercular" nodule from the lungs of a 

 Norfolk heifer with pulmonary actinomycosis. The nodule is a multiple 

 growth surrounding a bronchus, and is enclosed by a capsule, in the 

 vicinity of which the pulmonary alveoli are compressed. It is composed 

 of a number of separate neoplasms, and each of the latter is composed of 

 secondary centres of growth resembling the giant cell systems of baoillary 

 tuberculosis. The new growth is composed of ray-fungi, large multi- 

 nucleated cells, sometimes distinct giant cells, round cells, epithelioid cells, 

 and, surrounding them, fibrous tissue. On examination of the same 

 specimen with a higher power the typical rosettes of clubs are sometimes 

 surrounded by multinucleated cells, and sometimes small rosettes are 

 found like tubercle bacilli, in the interior of giant cells. From a pre- 

 paration stained by Ziehl-Neelsen, logwood, and orange-rubin. x 50. 



PLATE XXI. 



Fig. 1. — (a) A leucocyte containing the fungus in its earliest recognisable 

 form. (V) A large multinucleated cell containing the fungus in an early 

 stage with the club-form already visible, (c) A leucocyte containing a 

 small stellate fungus, (d) A large cell containing clubs arranged in a 

 small rosette, (e) A multinucleated cell with clubs arranged in a palmate 

 form. All the above are drawn from sections of actinomycotic tongues 

 stained by the triple method, x 500. 



Fig. 2. — A giant cell with large vesicular nuclei at the periphery, and in the 

 centre a fully formed rosette of actinomyces with a smaller growth within 

 a " daughter " cell. From a section of the tongue of an ox stained by 

 the triple method, x 500. 



Fig. 3. — A very large circular giant cell, with its ring of nuclei at the 

 periphery, enclosing several isolated tufts of actinomyces. From a section 

 of a nodule in the lung. Stained by the triple method, x 500. 



Fig. 4. — Three rosettes of actinomyces surrounded by a row of large, some- 

 what angular multinucleated cells. From a section of the tongue of an 

 ox stained by the triple method, x 430. 



