534 ON THE DOMESTIC PIG OF 



some varieties of the human species the supraciliaiy ridg-es, whether 

 underlain by sinuses or not, are very constantly developed into 

 great prominences. In a classification, indeed, of human ci'ania 

 proposed by Dr. Williamson i, ' skulls with the supraciliary ridg-e 

 so prominent as to overshadow the face ' formed one out of four 

 classes into which all crania were divided. It is not necessary to 

 go so far as this for acknowledging' that this character may be- 

 come, in the Suidae at least, a race character ^. 



The second in order of the three points which, taken together, 

 as they usually exist together, with the fourth, that relating to the 

 lacrymal, help us to identify Siis cristatus, is complexity of its 

 third molar, at least in male specimens, and specially the com- 

 plexity of that part of the tooth which lies posteriorly to the two 

 primary bicuspidate lobes. 



The division of the third molar which lies posteriorly to the two 

 anterior lobes is, in the male Sus cristatus, equal sometimes in size 

 to and sometimes even greater than both those other lobes taken 

 together. This is not often, though it is occasionally, the case in 

 Sus scrqfa, var. ferus, of modern times. Nor is it the case in the 

 females of Sus cristatus ; so that the greater development observed 

 in the males may perhaps be due to the working of the law of 

 sexual battle. The large size of the canines postulates a large 

 determination of blood to the jaw; and the large size of the third 

 molar, a tooth evolved at the period of sexual maturity, when the 

 animal 'venerem et praelia tentat,' may be, to use a word sug- 

 gested long ago by myself^, ' tautogeneous ' with it. Still the 

 fact that the third molars are small both- in Sus harhatus and Sus 

 barbirussa shows that this smallness cannot always be explained on 

 physiological grounds. 



The third point, that of the straightness of the naso-frontal 

 suture, appears to have some classificatory value, wli ether we look 

 at it with the light furnished by its importance and validity in the 



' ' Observations on Human Crania in Museum, Fort Pitt, Chatham,' 1857. 



^ It is observable in the pigmy Nepal pig, Porcula salviania, as also in the African 

 Potamochoerus. It does not appear to me that male Suidae possess it more markedly 

 than females ; and herein it differs from the supraciliary-ridge development as seen in 

 our own species, as also from the race-mark to be next mentioned. An analogous 

 eminence, rudimentary in S. papuensis, occupies the middle frontal line over an area 

 homologous with the human glabella in each of four pigs' skulls brought from the 

 Admiralty Islands by H.M.S. Challenger. 



3 'Nat. Hist. Rev.' Oct. 1861, p. 486, Article lY, p. =7. 



