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in all probability resemble those of deposits found elsewhere. The 

 muscular tissueadjacent to the diseased jaw, has been examined 

 by me, but I failed to discover any indications of morbid deposit. 



The brain and eye I have not yet had an opportunity of examining. 



A microscopic demonstration of the diseased bone, may be 

 obtained by cutting as fine a section of bone as possible with an 

 ordinary saw, further obtaining a thinner section than the first by 

 means of a fret saw machine, and lastly filing this down to an ex- 

 treme degree of tenuity. 



A section obtained in this way is seen under the microscope on the 

 table together with a specimen of bone obtained from a healthy 

 anima] In the diseased or osteosarcomatous section, the lacunoe 

 are enlarged and irregularly distributed in relation to the Haversian 

 canals which are twisted and thrown across one another in difiierent 

 directions. It must be mentioned here that there are two sections 

 of the bone one parallel with the ramus of the jaw and the other 

 directly transverse, these different directons were taken with a view 

 of showing the different relations of the lacunoe to the Haversian 

 canals. 



It is interesting in one of the morbid specimens to note the pre- 

 sence of triangular cells apparently occupying the mouth of the 

 lacunoe, for these appearances are to be seen also in the soft green 

 material of enlarged glands, where too may be seen ovoid cells with 

 triple nuclei floating over the field in abundance. 



The microscopic examination of the green material contained in 

 one of the subperitoneal glands shewed numerous round cells contain- 

 ing two or three nuclei, the granular cell substance becoming clear 

 on the addition of acetic acid, the appearances being identical with 

 those of a section of tuberculous lung. Several large three-cornered 

 cells containing nuclei were also noticed, and a dumb bell shaped 

 cell like that of a crystal of oxalate of lime. The soft yellow matter 

 from a secondary abscess in the jaw contained many thousands of 

 round cells with multiple nuclei and all densely picked, showing 

 activity of growth. 



The cause of this disease has been attributed to a blow or to 

 external violence. This cannot, however, be the real underlying 

 cause, because in the first place where a blow is struck on healthy 

 bone, the result, if any, would be ostitis or periostitis or simple 

 inflammation of the bone, which after a while would subside, or 

 would only leave behind some innocent thickening. 



Some explanation of the choice of site for the manifestation of 

 the disease, may be found in these considerations : — 



1. The head and jaws of horned cattle are more exposed to 

 injury than other portions of their bodies — obstacles being often 

 brushed aside by the heads or horns of beasts, and danger first 

 confronted by the same parts. Further, it is well-known that when 

 the disease breaks out in the upper jaw, it very often arises from the 

 fact that a briar or thorn has scratched the upper or lower eyelid, 

 given rise to subsequent irritation — provoked an open sore — and 

 developed into a scrofulous growth by the continued irritation and 

 rubbing which the beast has sought to relieve itself with. 



2, Again, just as in man, the favourite site of manifestation of 

 scrofulous disease is in the hip, so in cattle, it is quite probable that 



