HISTORY OF THE WORKS OF CUVIER. 155 



corn pa rat ive osteoloj^v of cacli osseous apparatus, as tliore is a general compara- 

 tive osteology of the wliolo s^'stem. 



The cranium^ tliat most complicated apparatus of tlie slvcleton, ]n'eseiits, in 

 all mammifers, a composition ver\' nearly tlie same; we may there follow each 

 bone, from man to the (piadrurnana, from the quadrumaiiato tlie carnivora, to the 

 rodentia, to the edentata, the pacliydermata, the ruminants, the cetacea; every- 

 where are recognized frontals, parietals, occipitals, tem])orals, the splienoid, the 

 ethmoid; and they are everywhere recognized as well by their position as their 

 use. It is as much if the interparietals appear to bo w^anting in certain species. 

 It is the same with the face. The bones of the nose, of the cheek, of the jaws, 

 of the palate, &c., are never wanting. The lachrymals alone fail in the phocse, 

 the doljihins, &:c. All other diflerences of nmnber are but apparent, and result 

 only from the greater or less promptness with which, according to the species, 

 tlie bones or parts of bones, constantly separated in the first stage of life, unite 

 and are confoimded in adult age. It is thus that, according to the species, the 

 occipital, the parietal, the sphenoid, the temporal, &c., ajipear sometimes single, 

 sometimes double, tripl(>, or quadruple ; but when we I'ecur to the fffitus the occi- 

 pital is always divided into four parts, the parietal into two, or rather into four, 

 counting the inter-parietals, which, in the end, constantly become united there- 

 with, the temporal into four, the body of the sphenoid into two, &c. Thus, in 

 the mammals, there is a normal numl)er for the bones of the cranium ; and when 

 this nundier appears masked by the obliteration of the sutures in the adult state, 

 the primitive division is alwa3-s reproduced and restored in the fa3tal state; and 

 what I say of the bones of the cranium may be said also of the bones of the 

 face, and of their more numerous subdivisions in the earlier stages. 



It would naturally be curious to see whether this singular analogy was main- 

 tained in the other classes, in the birds, the reptiles, the fish ; whether the same 

 nund)cr of bones is there everywhere reproduced ; whether, masked in the adult 

 state, it would appear in the foetal ; whether, in fine, reptiles and fish, in which 

 the bones of the cranium are always much more numerous, could be regarded as 

 corresprtuding in this respect to the early age of birds and mammals. This 

 interesting question was successively treated b}' M. Cuvier in reference to rep- 

 tiles {lieserchcs sur ks osscmcns fossiles, tome 5,) and to fish [lUstoire ndtiindle 

 ck'S poissoiis ;) it will suffice to indicate here the manner in which he has resolved 

 it relative to rejjtiles. , 



The reptile whose head presents the most striking traits of conformity with 

 tliat of the manuiiifers is the crocodile; from the crocodile i\I. Cuvier passes in 

 succession to the tortoises, the lizards, the serpents, and finishes with the batra- 

 chians, which conduct from reptiles to fish, as the crocodile from reptiles to mam- 

 mals. The head of the crocodile is composed of a much greater number of 

 bones than that of the adult mammifer, but by recurring to the foetus of this 

 last class we recognize in the head of the crocodile and that of the mammifer 

 very nearly the same number of bones. Thus ^I. Cuvier, after having found in 

 the crocodile, and in the same place as in the mammals, the intermaxillary 

 l)ones, the maxillary, the nasal, the lachrymal, the jngal, the palatine, the ethmoid,* 

 the body of the sphenoid, the parietal, finds also, and again in the same place, 

 the occipital, but divided into four parts, as it is in the foetus of mannnals, the 

 great wings of the sphenoid, vestiges of its lesser wings, its internal and external 

 pterygoid wings, but all these parts separate fi'om the body of the bone, as they 

 all are, except the last,t in the mammal at its earliest age; finally a temporal 



* With its cribriform lamina, its lateral winps, its superior cornets, its vertical lamina, but 

 all those pieces or dependences of the ethmoid, in great part, in a eartila<riuous slate. 



1 For this reason M. Cuvier gives the special name tit trnnnKcrsr. hour, to the external ptery- 

 goid ap(j})hysis, which, in the mammals, is not at any U'^c etrcctually separated IVom iho 

 groat teuiporul wing. It is, therefore, not properly a new bone, but a disinembernient of 

 the sphenoid, as the frontal bones, anterior and posterior, are dismembermenta of the frontal. 



