Bibliography. 1 53 



however, about which most anatomists have been for a long time 

 agreed, and they have become to a certain extent popular. 



In the second portion of the discourse the author grapples with a far 

 more abstruse and difficult subject. Since the publication of the spec- 

 ulalions of Goethe, Oken, Carus in Germany, and of St. Hilaire in 

 France, many attempts have been made to perfect the idea of the 

 philosophical "signification" of the parts of the skeleton. In evidence 

 of the difficulties which beset such investigations, and of the undigested 

 state in which many points still remain, it is only necessary 10 bear in 

 mind that the two ablest living naturalists have arrived at conclusions 

 widely different. Of their comparative merits however, it is not now 

 proposed 10 speak. Mr. Owen's views of the "signification of limbs," 

 as set forth in the discourse, are reproduced from his late treatise on 

 the Archetype and Homologies of the Vertebrated skeleton, and this 

 last has its basis on the labors of the German anatomists. One cannot 

 but be struck with the resemblance of Owen's "Archetypus" to the 

 " Schema vom Nerten skelel" of Carus,* the latter obviously in a very 

 crude embryonic condition ; the former giving evidence of more com- 

 plete development, and provided with appendages of which we do not 

 recognize even the germs in the latter. Mr. Owen, with other trans- 

 cendental anatomists, regards the whole skeleton as a series of verte- 

 brae, more or less modified, each vertebra consisting of its centrum or 

 body, an upper or mural arch protecting the brain or spinal marrow, 

 and a lower or hamal arch protecting the great blood vessels and the 

 organs of organic life. The lower arch is composed of ribs, their car- 

 tilages and siernum, which in the nomenclature of Mr. Owen, are re- 

 spectively pleur apophyses, lucmapophyses and hcemal spine. In many 

 fishes and reptiles, and in all birds, each inferior arch corresponding 

 with the thorax is provided with a small appendage of bone, which in 

 birds is attached to the middle of the rib, and in reptiles to the point 

 of union of the rib with its cartilage ; this Mr. O. calls the diverging 

 appendage. Two of these diverging appendages in the Lepidosiren 

 protrude through the muscles, and invested with the common integu- 

 ment constitute its single-rayed pectoral and abdominal fin. From the 

 single-rayed appendages to the acknowledged "arms" and "legs," 

 there are many transitional forms. He therefore regards arms and 

 legs as appendages to ribs and not as modified ribs, as maintained by 

 some anatomists of the transcendental school. The rib to which the 

 arm is attached, consists in the higher vertebrate classes, of the scapula, 

 clavicle and coracoid, one or both of the latter directly attached to the 

 first segment of the sternum, but having no connection with the spinal 

 column; now as every inferior arch corresponds with some centrum, 

 with the " body" of some vertebra, the question at once arises, to what 

 vertebra is the scapula a rib. Mr. Owen reasoning by exclusion, re- 

 gards it as the true and lawful rib of the occipital vertebra of the era- 

 niu m. I n the skeleton of the crocodile, every vertebra from the atlas 

 to the last lumbar, inclusive, is provided wiih its inferior arch, or a por- 

 tion of one, and so are the three anterior vertebrae of the cranium ; the 

 occipital being the only one which is destitute of it; if therefore the 



See Carus, von den Ur-thi ilan, dm Knocheu- mid Scbaleiujci -ustos, Tab. iv. %. I. 



. — July 



20 



