FISHES. 277 



The latter system, as in the birds and the greater part of the 

 reptiles, forms a layer, more or less vertical, articulated by its 



In the mean time, some important labours had been carried on in Germany upon 

 the subject to which our attention had been directed, but little notice was taken of 

 them by the Parisian anatomists, from a custom which is certainly now decaying. 

 In 1800 M. Autenrieth published, in the Zootormical Archives of Wiedemann, a 

 Memoir on the Anatomy of the Pleuronectes, in which he stated many remarkable 

 points connected with the head of fishes ; he considered the branchiostegal rays to 

 be the cartilages of the ribs, and that the bony branches which they bore as com- 

 posed of the OS hyoides and some portions of the sternum, &c., an opinion which wa3 

 entertained by M. Geoffroy in 1807, and which was the origin of the whole of his 

 theory of the branchial apparatus, as developed by him in his Philosophic Anatomique. 

 The operculum, according to M. Autenrieth, is the result of a division of the thyroid 

 cartilage, &c. ; but this learned physician devoted little attention in his memoir to 

 the analogy of the bones, with the exception of the apparatus of the tympanum, 

 which he still refers to the condyloid apophysis of the lower jaw, as H^rissant did in 

 the case of the square bones of birds. 



In 1811 a memoir by M. Rosenthal appeared in the Archives of Physiology of 

 Reil, on the Skeleton of Fishes ; in this the author described all the bones of the 

 head with a fidelity and clearness which were quite remarkable, but in which he has 

 been far less successful as to his investigation of their analogy. According to him, the 

 bone which is my ethmoid, and my two anterior frontals with my vomer, form the 

 upper jaw ; my mastoid bones are detached pieces of the parietal bones, my posterior 

 frontal represents the scaly part of the temporal, and my great ala the petrous 

 portion. He gives to the anterior sphenoid and to the orbitary wings the names of 

 the body of the sphenoid and its wings. The sphenoid, properly so called, is desig- 

 nated by him the bone of the base of the cranium. His conclusions and mine on 

 the other bones of the cranium completely agree. 



With respect to the face, M. Rosenthal has come to no decided inferences. My 

 intermaxillaries and my maxillaries, according to him, are only divisions of a single 

 intermaxillary ; he calls a square bone that which I have named the temporal, and 

 gives to the other bones of the palatine and pterygoid apparatus, only vague names 

 which do not indicate their analogy. 



M. Oken, in a programme of 1807, had considered that the cranium was composed of 

 three vertebrae, and he calls it the head of the head ; the nose was his thorax of the 

 head, and the jaws he thought represented the arms and the thighs. These com- 

 parisons made very diflFerent impressions on men's minds, and applications of them 

 ■were made to fishes. 



In 1815 M. Spix, in his work called Cephalogenesis, saw also in the cranium of 

 the vertebrated animals three vertebrse, but the bones which surround the nose 

 appeared to him analogous to the hyoid apparatus, and those of the jaws the repre- 

 sentatives of the anterior and posterior extremities. He there gives figures of the 

 heads of the pike, of the cod, trout, eel, silurus, and the carp, but he has published 

 no acanthopterygian. In his system, my ethmoid is the nasal, my anterior frontal 

 the lachrymal, my anterior sphenoid the ethmoid, my mastoidean the scaly temporal, 

 my posterior frontal a portion of the jugal, my petrous bone a part of the lateral and 

 occipital. As to the rest of the bones of the cranium, he concludes as I do. In the 

 face, he refers the suborbitals to the jugal. My transverse bone and my palatine 

 form together, according to him, the pterygoid bone, and what I call pterygoid he 

 designates the true palatine. The other bones of the pterygo-tympanic apparatus 

 answer in their combination, he says, to the annular portion of the tympanum, but 

 he recognised, as I do, the intermaxillaries and the maxillaries in the bones com- 

 monly called the jaws. 



It is M. Spix, if I am not mistaken, that first saw the little bones of the ear in 

 the opercula, but he arranges them differently from M . Geoffroy. According to him, 

 the preoperculum is the malleus, the operculum is the incus, and the suboperculum 

 the stapes. 



M. Oken, in the Isis, No II, of 1818, has translated my various notes on this 



