Botany and Zoology. 129 
The tympano-mandibular and the ‘hyoidean arches had both been 
recognized as resembling ribs. A like homology of the scapula had 
ment from its natural or typical connexions in all the air-breathing 
vertebrata. 
The enunciation of these correspondences has sometimes been re- 
ceived by anatomists conversant with one particular modification of the 
general type, with as little favor as those of the “ cann 
ans. 
Prof. Owen adduced instances of the displacement of different ver- 
tebral elements to subserve special exigencies, as that of the neura- 
pophyses in the bird’s sacrum, and that of the ribs of the human tho- 
. P 
modification of precisely the same kind, and differed only in degree. 
In the crocodile every cervical as well as every dorsal vertebra had its 
ribs; and in the immature animal the same elements existed, as distinct 
€ general homology of the locomotive members as developments 
of the diverging appendages of the inferior vertebral arches, was illus- 
trated, and the parallelism in the course of the modifications of all such 
appendages pointed out. As the scapular arch belongs to the skull, so 
iS appendages, the pectoral or anterior members, were essentially parts 
of the same division of the skeleton segments. : 
Asa corollary to the generalization that the vertebrate skeleton con- 
sisted of a series of essentially similar segments, was the power of 
tracing the corresponding parts from segment to segment in the same 
skeleton. The study of such “serial homologies” had been com- 
menced by the unfortunate Vicq. d’Azyr, in his memoir * on the paral- 
lelism of the fore and hind extremities ;’ and similar Telations could 
traced through the more important elements of the series of vertebra. 
Prof. Owen believed it to be an appreciation of some of these hornol- 
ogies that lay at the bottom of the epithets, “scapula of the head, 
sted merely in 
“pecial instead of a general name to express the serial homology rightly 
discerned, in some of the instances, by the acute German anatomists. 
Seconp Serizs, Vol. IV, No. 10.~July, 1847. 1 
