276 PROCEEDINGS OP THE ACADEMY OP 



the centuries that have elapsed, since man first appeared upon the surface of 

 the earth, the ethnical peculiarities which appear to have originally charac- 

 terised the laws of cranial development in the different races of men, have 

 become so masked or modified by hybrid interminglings of varied degree 

 and kind, that the great principle of the correlation of forms is scarcely availa- 

 ble in inferring from one or more fragments of a skull the typical form of that 

 skull. Cuvier, the discoverer of this important principle of palaeontology, 

 regarded every organized being as a whole, whose different parts correspond to 

 each other in such a manner that none can change without the others changing 

 also. Consequently, to him not only each part, but each fragment of apart, ap- 

 peared to be the index of all the others. He asserted that not only the class, 

 but the order, the genus, and even the species are expressed in the form of each 

 part, in the smallest apophysis, the smallest bony facet. Guided by this teleo- 

 iogical principle, the sagacious Cuvier, from the examination of a single tooth, 

 was enabled to announce the character of the entire skeleton of an extinct reptile. 

 The jaw bone and teeth of an extinct species of animal then unknown (Phascolo- 

 Iherium Bucklandii) he correctly ascribed to a marsupial quadruped allied to the 

 opossum. In like manner the fragment of a fossil femur, found in New Zealand, 

 was referred by Prof. Owen to an extinct genus of tridactyle Struthious birds. 

 The correctness of this reference was afterwards attested by the discovery of 

 numerous remains of several species of this genus. So also, Prof. Leidy, fol- 

 lowing the same great law of the harmonization of forms, was enabled to as- 

 sign the fragment of a fossil molar tooth, from Missouri Territory, to a species 

 of rhinoceros. Subsequently, he received from the same place fragments of 

 the maxillae and cranium of this species sufficient to confirm positively his 

 opinion. Still more recently he referred a fragment of the anterior portion of 

 a fossil upper jaw, from the valley of the Niobrara river, to a species of camel, 

 and this reference was confirmed by the discovery of an entire jaw of the ani- 

 mal bearing the peculiar hook-like process, which differentiates it from all 

 other ruminants. 



But, though the palaeontologist and comparative anatomist can, from minute 

 fragments of bone, reconstruct many of the extraordinary species of animals 

 that flourished in earlier geological epochs, yet the student of human cranio- 

 graphy can seldom, with any certainty, indicate from a fragment the type and 

 race of a skull. The palaeontologist is assisted to his conclusions by the law 

 of co-existing elements or harmony of forms, and when this fails, as it does 

 at times, and as it occasionally did even in the hands of its illustrious dis- 

 coverer, he can resort to the comparison of the fossil remains he may be study- 

 ing with the similar parts of animals now existing. The craniographer cannot 

 avail himself of this law of correlation. The existence of numerous transi- 

 tionary forms, partly natural, partly hybrid, occupying places between the 

 leading, typical stocks, and causing these latter to graduate into each other, 

 in some instances almost insensibly ; the difficulty of distinguishing between 

 natural and hybrid sub-types ; the existence of artificially deformed crania 

 among different races in both hemispheres, some of them being purely arbi- 

 trary or conventional, and some of them imitations of natural but little known 

 forms, all constitute serious obstacles to the practical application of this law 

 to human crania. A still greater difficulty, moreover, is found in the fact 

 that, in its practical working, this law is seen to be more generic than specific. 

 In other words it differentiates genera better than species ; species better than 

 varieties. With the latter, though theoretically true, it is practically valueless. 

 Cuvier himself was unable to point out specific osteological differences between 

 the lion and tiger, the horse and ass, the dog and wolf, the leopard, panther, wild 

 and domestio cats, &c. Pie was unable, consequently, to satisfy himself of the 

 precise organic form or specific type to which the fossil representatives of these 

 species belonged. Even, in regard to living species, Cuvier acknowledged that 

 " La classe des poissons est de toutes, celle qui offre le plus de difficultils quand 



[Sept. 



