44 THE DESCENT OF MAN. 



which a long-lost structure is called back into existence, 

 might serve as the guide for its full development,, even after 

 the lapse of an enormous interval of time. 



Prof. Canestrini, after discussing the foregoing and 

 various analogous cases, arrives at the same conclusion as 

 that just given. He adduces another instance, in the case 

 of the malar bone,* which, in some of the Quadrumana 

 and other mammals, normally consists of two portions. 

 This is its condition in the human foetus when two months 

 old ; and through arrested development, it sometimes 

 remains thus in man when adult, more especially in the 

 lower prognathous races. Hence Canestrini concludes that 

 some ancient progenitor of man must have had this bone 

 normally divided into two portions, which afterward be- 

 came fused together. In man the frontal bone consists of 

 a single piece, but in the embryo, and in children, and in 

 almost all the lower mammals, it consists of two pieces 

 separated by a distinct suture. This suture occasionally 

 persists more or less distinctly in man after maturity ; and 

 more frequently in ancient than in recent crania, especially, 

 Canestrini has 



as Canestrini has observed, in those exhumed from the 

 Drift, and belonging to the brachycephalic type. Here 

 again he comes to the same conclusion as in the analogous 

 case of the malar bones. In this, and other instances 

 presently to be given, the cause of ancient races approach- 

 ing the lower animals in certain characters more frequently 

 than do the modern races, appears to be, that the latter 

 stand at a somewhat greater distance in the long line of 

 descent from their early semi-human progenitors. 



* " Annuario della Soc. del Naturalist! in Modena," 1867, p. 83. 

 Prof. Canestrini gives extracts on this subject from various authori- 

 ties. Laurillard remarks, that as he has found a complete similarity 

 in the form, proportions, and connection of the two malar bones in 

 several human subjects and in certain apes, he cannot consider this 

 disposition of the parts as simply accidental. Another paper on this 

 same anomaly has been published by Dr. Saviotti in the " Gazzetta 

 delle Cliniche," Turin, 1871, where he says that traces of the division 

 may be detected in about two per cent, of adult skulls; he also re- 

 marks that it more frequently occurs in prognathous skulls, not of 

 the Aryan race, than in others. See also G. Delorenzi on the same 

 subject ; " Tre nuovi casi d'anomalia dell' osso malare," Torino, 1872. 

 Also, E. Morselli, " Sopra una rara anomalia dell' osso malare,' 

 Modena, 1872. Still more recently Gruber has written a pamphlet 

 on the division of this bone. I give these references because a re- 

 viewer, without any grounds or scruples, has thrown doubts on my 

 statements. 



