318 CAUSE OF POLL-EVIL. [BOOK II. 



poll-evil. On passing the hand over the part, the 

 animal may be observed to flinch from the touch ; 

 but this symptom is seldom attended to, and it 

 makes its way inwards, bursts in the cavity of the 

 abdomen, and kills the patient. 



POLL-EVIL. 



Causes. — Next to a diseased habit of body, as just 

 above noticed, which is found to predispose a certain 

 description of horses to contract tumours in various 

 parts of the body, the poll-evil is frequently occa- 

 sioned by a blow, or gall, of a very trivial nature, 

 if it do not come on without this kind of excitement. 

 The action of the head is very great with some 

 horses, arising probably from an itching in the 

 upper part of the cervical ligament, where it is at- 

 tached to the vertebras of the neck ; and this causing 

 irritation, we need not hesitate long in accounting 

 for the inflammation that affects the muscle which 

 interposes between it and the knoll-bone, in a cavity 

 that is greater with some breeds of horses than 

 others. This variance in conformation is exempli- 

 fied in the whole length portrait of a skeleton which 

 is prefixed to this volume, wherein the cavity that 

 should form the seat of this disease is scarcely per- 

 ceptible ; whilst the small figure, inserted at page 

 68, to illustrate the uses of the cervical ligament, 

 has this cavity of the usual extent. Of course, this 

 latter would be still more predisposed to contract 

 poll-evil than the former, which was a peculiarly 



