DISEASES OP THE BLOOD. 171 



into question (see ^' Synopses of Continental Veterinary 

 Journals/^ ^ Veterinarian^' February and Aprils 1880; also 

 Dr. Greenfield's Lecture IV, February number of ' Vete- 

 rinarian/ 1880) by MM. Arloing, Cornevin, and Vernaut. 

 These diseases are not reproducible one from the other, do 

 not occur together in a herd subjected to deleterious influ- 

 ences, and no bacteria have been generally recognised as 

 occurring in the blood in black quarter, nor did inoculations 

 with that fluid give rise to any attack of anthrax or of 

 the emphysematous disease (except in Dr. Greenfield's 

 case). Cattle of all ages aro liable to become affected, 

 but this disorder generally appears in young stock aged 

 from six months to two years, which have been changed 

 from poor to rich pasture, especially low-lying land. Such 

 animals thrive with rapidity until they attain a high state 

 of plethora, when some of them, perhaps, become lame. 

 A swelling commences in some part of the body, especially 

 the hock. This is very hot and painful ; it is apt to be 

 mistaken for an injury. It rapidly extends up the limb, 

 causing very considerable tumefaction, at first highly 

 painful. Later insensibility may be observed in the parts, 

 they become gangrenous, cold, and crepitate on pressure, 

 in consequence of accumulation of gases in the subcutaneous 

 areolar tissue as a result of decomposition. When cut into 

 it is found to be produced also by accumulation of putrid, 

 sanious, and yellow gelatinous material underneath the skin 

 and between the muscles of the part ; also patches of black 

 pulpy substances may be observed in various parts of the 

 tumour. Similar swellings in other cases occur in the 

 fore limb, breast, back, or sides, manifesting the charac- 

 teristic changes mentioned. Constitutional symptoms run 

 high at this stage. The earliest signs may be observed 

 before any local disorder when a herd is under close super- 

 vision. They are those of general disorder and acute fever. 

 The occurrence of tumefaction is said to be accompanied by 

 diminution in the constitutional symptoms, but we can 

 hardly regard this as correct; the change consists rather 

 in inability of the constitution any longer to maintain the 

 acute fever. The animal rapidly loses strength, maintains 



