44 J. Cockburn — On an cihnormality in the Tiorns of the Hog -deer. [No. 2, 



VII. — On an alnormality in the horns of the Hog-deer, Axis porcinus, 

 with an amplification of the theory of the evolution of antlers in 

 Ruminants. — By John Cockbuen, Offg.ind Asst. to Supdt. Indian 

 Museum^ Calcutta. 



[Read March 1882.] 



The specimen exhibited to the meeting is a frontlet of the Hoo'-deer 

 in -which the left horn is abnormally developed as in a stag of the elaphine 

 group. The frontlet is a specimen that belonged to the Asiatic Society's 

 collection and is without history. There is, however, fair presumptive 

 evidence that the horns belonged to a feral animal.* Before proceedino- to 

 any explanation of the variation a description is necessary. 



The right horn is normal and measures 14" from burr to tip along 

 the curve. The brow tine 3|'V ^^e external tine 5'', internal tine 2\". 

 Circumference at burr 5-| of beam midway 2f . The left horn has five 

 tines on it, as in a stag of ten, and the beam describes a sweeping curve 

 posteriorly. The burr and brow tines are normal, though the latter is 

 slightly curved inwards ; an inch and a half further up the beam is a tine 

 measuring 3^" in length which I take to be representative of the bez tine. 

 This tine, though otherwise justly proportioned, is curved inwards and back- 

 wards. Three and a quarter inches further up the beam is a third snag 

 measuring 2^" along the curve ; this snag though flattened and distorted I 

 take to be analogous to the royal tine. Lastly the tip is bifurcated, its 

 appearance being that of the sur-royal in Cervus canadensis. These snags 

 are palmated and the inner furcation, which has lost its tip, grows parallel 

 to the inner tine C on the opposite horn. 



Abnormalities in Cervine horns are not uncommon. Judge Caton in 

 his recent work " On the Antelope and Deer of America" discusses the 

 question and attributes these growths to accidental injury to the horn, 

 while tender and growing. Admitting that the majority of abnormal horns 

 come under this category, I am nevertheless inclined to think that the 

 specimen under review is to be otherwise explained. As a disci^^le of the 

 doctrine of evolution it appears to me more rational to attribute the con- 

 dition of the left horn to reversion or atavism. The circumstance of the 

 variation being unilateral does not invalidate my hypothesis ; polydactylism, 

 the occurrence of supernumerary mammae, and other phenomena of this 

 nature being very frequently unilateral. 



* The horns are bleached as if by exposure, and the polish where visible appears 

 to me rather that of a feral than domestic animal. 



