NEUROMATOUS TUMOURS. 417 



ject ; but in the lower animals I know of only one set of nerves 

 upon which they appear, and as the result of an operation, namely, 

 upon the plantar nerves, after their division for foot lameness. 



These tumours appear within an indefinite period after the 

 operation (neurotomy) ; in one case four years had elapsed 

 before they began to form. They are of a solid firm consistence, 

 composed of a fibrous stroma, the fibres of which have a wavy 

 outline, running parallel to or interlacing with one another, 

 and having scattered throughout them numerous groups of cells 

 more or less closely packed together. Eokitansky says — 

 " These tumours lie between the fasciculi of the nerve, and are 

 interwoven with their neurilemmatous sheath ; and it is a 

 remarkable and no less important general rule, because of the 

 symptoms which may result from its presence, or which may be 

 set up by operations performed on it, that neuroma is never 

 deposited in the centre of a nerve, but at its side, so that only a 

 small part of its fasciculi is displaced. The displaced fasciculi 

 are spread abroad and stretched over the tumour, while the 

 greater mass of the nerve remains on the other side uninjured, 

 and with its fibres in connection with one another." 



These tumours are found as rounded or oval bodies, with 

 their long diameter along the course of the nerve ; varying in 

 size, but never very large ; moveable in the transverse but not in 

 the long direction. They are always on the superior division 

 of the cut nerve. They sometimes cause great pain, manifested 

 more particularly when the horse is standing still. He will 

 then often lift his foot from the ground, as if the pain were 

 lancinating; but the lameness is not so evident when he is 

 made to move. When the tumour is pressed upon, or handled 

 in any way, the patient evinces acute agony. Sometimes, how- 

 ever, these tumours, although of some magnitude, cause no in- 

 convenience ; but they are apt to be struck by the opposite foot, 

 and so cause the animal almost to faU to the ground. They 

 sometimes make their appearance in a short time after the 

 operation of neurotomy, and are the result of a badly performed 

 operation; the operator having divided the nerve below the 

 upper angle of the wound in the skin, thus leaving a portion 

 of it in the wound, which, becoming embraced in the reparative 

 material, forms a nucleus for the growth of the neuroma. 



The only treatment is excision by the knife. 

 2 E 



