532 ON THE DOMESTIC PIG OF 



affinity to the 8ms indicus long before tlie frontal sinuses are 

 fully developed; and I am inclined to think it may sometimes, 

 though certainly not always, be detected in very young specimens 

 of Sus scrqfa, yar. j^erus, such as the one figured by Nathusius, /. <?. 

 (Taf. i. fig. I, Taf. iii. fig. 13). Though the fulness of this region 

 is due in the adult partly to its being underlain by frontal sinuses, 

 which are relatively small in the early stages of the animal's life, 

 there is still some justification for regarding this structure as an 

 instance of the retention by the adult of an early structural ar- 

 rangement ; for it is easy to understand that the contour described 

 by the external tables in early youth may be carried out conform- 

 ably by the blood-vessels of the scalp as the animal grows older. 

 A parallel to such a process is furnished to us very frequently, 

 though by no means so nearly universally, by the retention in the 

 adult Sus cristatus of that fulness and convexity of the vertical 

 aspect of the fronto-parietal region which is characteristic of Sus 

 scrqfa both wild and domestic, as well as of 8'ics cristatus and 8us 

 indiGuSy at birth ^. Lieutenants W. E. Baker and H. V. Durand, 

 in their paper on ' Subhimalayan Fossil Kemains of the Dadupur 

 Collection,' in the ' Journal of the Asiatic Society of Bengal,' vol. v. 

 1836, p. 664, observe of the two fossil skulls which they describe, 

 that in both 



' there is in the frontal plane a total absence of convexity. As this plane ascends 

 there is a tendency to concavity, in consequence of the parietal crests being more 

 strongly marked than in the existing species, and thus producing the appearance of 

 a gentle hollow where, in the common wild hog, there would be a gentle swell.' 



Further on, in the same paper, the authors remark : — 



' From the form of the cranium, the shape of the canines and incisors, and the other 

 points in whieh the fossil differs from the existing species of the country, a specific 

 difference may be inferred; for the dissimilarity, although iess than that which occurs 

 between the Babyrussa, the /S^. larvatm, and the Sus scrofa, or common hog, is too 

 remarkable, particularly in the shape of the canines of the lower jaw, to admit of the 

 fossil being considered as a mere variety of the Sus scrofa.^ 



Sir Walter Elliot, however, to whom I owe this reference as 

 well as other things, writes me to the effect that the skulls sent by 

 him to me 



* do not seem to differ much from the Subhimalayan fossil specimens figured and 

 described,' 



as above specified. And it is worthy of being put upon record that 



^ See Nathusius, pi. i. figs i and 3, pi. iii. fig. 13, and pp. 3 and 13. Compare the 

 mesial fulness in the frontals of S. papuensis. 



