871.] 405 [Wilder. 



arises the question as to the relative value of nervous and osseous 

 ! associations. 



The previous question suggests several others which have already- 

 been much discussed. 



1. What is the morphical relation between the membra and the 

 omozone and ischizone ? 



2. What is the morphical relation between these arches themselves 

 and the skeletal axis ? 



3. What relation do these arches hold to each other ? 



It is now generally admitted that the scapula and ilium are not 

 properly parts of the membra, although the former, especially, appears 

 to be such in many quadrupeds, which lack the other elements of 

 the omozone; and although the telical antagonism of position 

 between scapula and ilium has led me to include these bones in the 

 presentation of evidence (45, 20,): but I am now convinced that this, 

 like some other considerations (the convergence of the dorsal spines 

 toward the centre of motion, and the antagonism of membral inter- 

 nodes), must be eliminated from the discussion. 



The relation between the membra and the membral arches has been 

 ably discussed by Humphrey, (36, 23); also by Wyman, (55, 264), 

 who concludes that "in their primary condition, limbs do not appear 

 to be dependencies of the scapular and pelvic arches any more than 



the teeth are dependencies of the jaws, with which, 



notwithstanding their totally different origin they become so intimately 

 united at last." Still, and in spite of the probability that the omo- 

 zone serves, especially with fishes, as a heart protector, there seems 

 no reason to doubt that both omozone and ischizone are formed 

 with reference to the attachment of the membra, and are shifted in 

 position in conformity with the needs of different species. Upon 

 this point consult also Coues, (70, 194, note). 



This leads to the second question as to the morphical relation 

 between the omozone and ischizone and the rest of the skeleton. 



The view of Owen that the " scapular arch is normally the haemal 

 arch of the posterior occipital vertebra of the skull " has been en- 

 dorsed by no real investigator of the subject, 1 and has on the contrary 

 been vigorously combated by Goodsir, (240, 199,) Humphrey. (36, 26), 

 Agassiz, Wyman, (55, 260) Spencer, (299, 522) and Parker, (292, 

 87); like some other views of the eminent English anatomist, this 

 must be regarded as a motion unseconded, and therefore not open 

 to debate. Upon this question consult Parker, (292), Cleland (65,) 



