284 BOMBAY NATURAL HISTORY SOCIETY. 



another irregular horn on one of the limbs; thus the animal seems to have had a 

 tendenoy to such growths (kevatogenous diatheses'). There are many such cases 

 on record both in man and in the lower animals, but irregularities of this nature 

 are always worthy of careful examination and record, for irregular horns may be 

 of several different kinds: — 



I. — Commemorative or Atavisms. — Recurrences to original type, as when indi- 

 viduals of hornless breeds of cattle develope horns ; true frontal horns as occasion- 

 ally seen in horses may serve to illustrate affinities or possibilities of future 

 development, 



II. — Degenerated Organs. — Horns about the limbs are generally of this nature, 

 and somewhat resemble the "warts" of the fore and hind limbs of the horse, the 

 rudimentary claws of oattle. It would have been of interest to know whether the 

 horn of the limb of this goat was a degenerated limb or not. 



III. — Accidental displacements of normal horns, 



IV. — Simple warty growths — Thickenings of the epithelium assuming a horny 

 character, and physically compelled to become conical in forms known to cutaneous 

 surgeons as cornua. 



V. — Compensatory.— Developed as atonement for loss of these natural means 

 of offence and defence ; as in the case of which I show a drawing made by me 

 from the original in the Museum of the Royal Veterinary College of London. 

 The horn of a cow was broken, and from the side of the stump shot; out at right 

 angles a true young hollow horn, a phenomenon of sprouting which is mos-t 

 remarkable in an animal so high in the scale as the ox. 



VL — Physiological. — Such as the natal collosities of the monkeys (seen also in 

 old and ill-tended dogs) and the horny pads of the knees, stifles, elbows, and 

 brisket of the camel. 



In the case in question the horn is neither commemorative nor a degenerated organ, 

 for it is not natural to any animals allied to the goat to have horns on their ears, 

 It is not compensatory, for the ordinary horns of the animal are well developed ; 

 we have no reason to believe it could have been produced to meet a physiological 

 emergency. It might have been a horn the skin to form which had accidentally 

 before birth become transferred by grafting from the frontal region to an ear 

 resting against it, but in that case the ordinary frontal horn should be deficient 

 or defective, which is not the case. Loose frontal horns of cattle are very common 

 especially in the more improved breeds and in females, rather than males, the 

 core of the horn then degenerates at its root into a simple ligament or disappears, 

 altogether, and the organ may be far detached from its normal position. We have 

 no evidence of suoh being the case here, but the reverse, for the ordinary horn 

 occupies the usual position. Wo are thus, by exclusion, compelled to fall back on 

 the view that we have to deal with a keratoma or horn tumour, an epidermal growth 

 assuming the form of a conical horn. I have found recorded among my notes a 

 case of "a horn on the tip of a cow's ear," as described by a professional friend of mine 

 who saw the animal alive, which probably was of the same nature as this. Warts 

 on the ears of cattle are by no means rare and keratoid growths are often dealt with 

 in works on surgery and of the skin. Bland Sutton has recently brought out an 

 interesting paper on the subject in the Journal of Comparative Medicine and 

 Surgery. 



