The causes from which it originates are obscure, and cannot be very well defined. Still, they may be arranged under the heading of any of the morbific causes which may excite an excess of inflammatory action at the end of the cord. Amongst these may be enumerated all violent tractions upon the cord at the time of the operation; all unnecessary manipulations during the process of cicatrization, such as the too frequent introduction of the finger into the wound with destruction of the granulations already adherent to the cord, and the application of the appliances for its division too low down upon it, leaving that organ hanging too much, and the retraction of the organ being insufficient to retain it in the inguinal sac. Still, as a champignon may be developed in the absence of all these causes, it would seem that their growth may be attributed also to some specific idiosyncrasy in the animal affected, the true nature of which cannot be very accurately or easily understood. It is held, however, by certain German and Russian authors that exposure to cold exercises a great deal of influence in the development of this affection, and observation has largely established the fact of its greater prevalence during cold seasons. _Symptoms of extra-scrotal champignon._--This is otherwise known in the terminology of some pathologists as _true_ or _superficial champignon_. It develops itself at the cut extremity of the cord as a granulating mass, of a red color, varying in size, its growth, nevertheless, allowing the cicatrization of the skin to progress in such a manner that it forms a point of attachment from which the tumor seems to proceed. This form of it is usually of little account, as it may easily be removed before it has attained to troublesome dimensions. When of considerable proportions, however, it may interfere materially with the act of locomotion by causing pain in the cord, upon which it drags more or less. It is not often or necessarily accompanied by constitutional disturbance, excepting in cases of excessive suppuration, which may sooner or later undermine the general health by exhausting the stamina of the patient. If instead of showing its greatest development on the surface of the scrotum, it occurs beneath it, a greater or less degree of swelling will appear on one or both sides of the inguinal region, the swelling being somewhat hard, possibly the seat of one or more fistulous tracks resulting from abscesses which have at times opened, discharged, and closed; the animal showing a certain amount of stiffness in the action of the hind legs. In this case we shall have to adapt our treatment to the _deep champignon_ of Zundel, under one of its three forms of _extra-inguinal_, _intra-inguinal_, and _intra-abdominal_.