MALIGNANT TUMOURS. ' 413 



of a natural tissue ; they do not appear as infiltrations displacing 

 or overwlielming the original tissues of their seat ; they do not 

 show a natural proneness to ulceration; nor is the ulceration 

 which may happen in one through injury or disease prone to 

 extend into adjacent parts ; they do not grow at the same time 

 in many different tissues. 



" Of recurrent tumours ; the chief destructive characters are, 

 that, like innocent tumours, their structures resemble those of 

 the natural tissues, but only in a rudimental state, or in con- 

 ditions that may be likened to malformations; that they do 

 not appear as infiltrations ; that their ulceration, to which, how- 

 ever, they are more prone than most innocent tumours, is not 

 apt to extend into adjacent parts; but that, like malignant 

 tumours, they do sometimes appear in organs distant from 

 their first seat, and are exceedingly prone to be repeatedly re- 

 formed after complete extirpation." — (Paget's Lectures on Sur- 

 gical Pathology) 



I have made the foregoing extensive quotation from Paget, 

 as it clears up, in a most masterly manner, the great confusion 

 prevailing amongst veterinarians upon the nature of the limited 

 variety of tumours which are seen in veterinary practice, and it 

 also shows how rare an affection cancer is in the domesticated 

 animals. Numerous cases are recorded in the Veterinarian; 

 but, to my mind, the proof that many of them were really 

 cancerous is quite insufficient. At the same time, it cannot 

 be said that the horse is not subject to cancer, although some 

 veterinarians believe such to be the case. After examining the 

 various reports upon cancer, in the Veterinarian and Edinhurgh 

 Veterinary Review, I am of opinion that the following cases were 

 those of malignant disease, namely:-^ 



1st. Hard cancer in vagina and mammary glands of a mare, 

 reported in the Clinique of the Veterinary School of Lyons. — 

 Veterinarian, 1839. 



2d, Hard cancer in submaxillary, mesenteric, inguinal, and 

 other glands, reported by Mr. A. Cherry, London. — Veterinarian, 

 1855. 



M. Epithelial cancer of the bladder of a horse, reported by 

 Messrs. C. andD. Shorten, Ipswich. — Veterinarian, 1855. 



Uh. A case of scirrhus of the stomach, reported by Mr. E. 

 Coleman, Sutton. — Veterinarian, 1857. 



