PRINCIPLES OF VETERINARY SURGERY 503 



The fistulcE are seldom very deep, but they have a sinuous 

 tract. On digital exploration the fistula appears to be car- 

 peted with a lining analogous to the pyogenic membrane of 

 an abscess. They discharge a purulent product containing 

 the "yellow grains" in suspension, which are characteristic 

 of the disease. 



The local symptoms for a time co-exist with a satisfac- 

 tory state of health. For months the tumor may grow with- 

 out causing any perceptible inconvenience to the animal. It 

 is only when the neoplasm has attained a considerable vol- 

 ume, when it has distorted the buccal cavity and loosened 

 the teeth, and when it has ulcerated the mouth, that it be- 

 comes troublesome. The movement of the jaws is then lim- 

 ited. The prehension of food is difficult and mastication is 

 painful and insufficient. In this condition of inconvenience 

 and pain the subject grows lean and becomes wretched. 



Spontaneous recovery is exceptional, and it is rarely ever 

 cured by the different methods of treatment recommended. 

 In 1884, Johne distinguished two varieties of the disease 

 afifecting the jaw : one which originates in the bone tis- 

 sue, or myelogenic actinomycosis, and a second which has 

 its origin in the periosteum, or periosteal actinomycosis. 

 In the first case, and according to Johne's conception, the 

 tumor is exclusively osseous, while in the second it is formed 

 at the expense of the periosteum and the subcutaneous con- 

 nective tissue, The latter is then especially fibrous and 

 hence less grave than the first. 



Medical men acquainted with the disease accept Johne's 

 classification. It might perhaps explain the difference of 

 the results obtained with iodine treatment, which may tem- 

 porarily cure the fibrous form, but has nO' effect on the 

 myelogenic variety. 



Actinomycosis of the Tongue. — This form is rare in 

 France. It has been observed by Godbille and by Rigal. 



