IN THE LIMBS OF MAMMALIA. 23 



He then goes on to say : " The anterior extremity having been thus untwisted, the 

 radius and tibia (which he considers analogous bones), are on the inside, while the ulna 

 and fibula are on the outside ; also the thumb and great toe, and the little finger and little 

 toe, are respectively inside and outside ;" all which correspondences do of course confirm 

 him in his preconceived idea; but since, as has been shown, they are only analogies, not 

 homologies, they do not in the least affect the true view of the case. Anatomy should be 

 studied from the centre outward, as well as from the circumference inward. 



Under the head of " Evidence of the torsion of the humerus," Mons. Martins adduces the 

 raised line which passes from the condyle across the front of the bone, and the general 

 direction of the vessels and nerves of the upper arm; not perceiving that both are only 

 physiological provisions, in the one case for the attachment of muscles, and not appearing 

 till needed ; and in the other for the better protection of the vessels and nerves, as is, 

 moreover, equally the case in the lower limb. What can Mons. Martins think of the 

 numerous ridges and apparent contortions presented by all the bones of the great ant- 

 eater (Myrmecophaga jubata) ? It would be difficult to determine how many degrees 

 they should be untwisted to conform to his ideas of their normal condition. Unfortunately, 

 Mons. Martins has not taken warning from his predecessors, and is, like them, haunted with 

 the idea of parallelism, but his view has, in one respect at least, the merit of originality ; 

 for while they humbly took things as they found them, and patched them up as well as 

 they could, he boldly declares that things are not what they seem, or at least seem not 

 what they ought to be, and with his own hands sets them aright. His preestablished 

 theory is a very Procrustes' bed, to which facts must be adapted, whatever their real 

 import. 



Having done this violence, however, his conscience reproaches him, and he thinks to 

 appease outraged Nature by conceding what he is pleased to consider a "metaphysical 

 difficulty," (p. 65.) Here, after admitting that no such insisting ever takes place, and that in 

 youth, before the development of the muscles has raised lines on the bones, no evidence 

 of torsion exists, he declares that " this torsion of the humerus is not mechanical, but only 

 virtual, though producing the same effect as if it were real." Also that "natural history 

 is full of such facts." The examples he adduces are undoubtedly such ; but a sounder 

 illustration is to be drawn from the position of the whole anterior extremity ; this is now 

 admitted by all to represent the pair of ribs with their diverging appendages of the 

 occipital cranial vertebra, not only in fishes where the contact is actual, but also in all 

 other vertebrates, man included, as stated above. But the reasons for this conclusion 

 are very weighty, since in addition to the fact that the homologous parts in fishes are 

 actually so attached, there else would be a vertebral segment minus a pair of ribs, and a 

 pair of ribs minus a vertebra ; nor indeed is it certain that even in the higher vertebrates 

 the anterior extremity is not at some time in contact with the cranium, while the other 

 evidence is absolutely conclusive as to the morphological relationship. So that we may 

 say there is a positive necessity for so disposing of these otherwise vagrant vertebral ele- 

 ments. But no such necessity compels us to assume a torsion of the humerus in order to 

 gain a clear and philosophical view of the vertebrate limbs ; and even if in our opinion it . 

 did, no such torsion ever takes place, as is acknowledged by Mons. Martins ; so instead 

 of a metaphysical difficulty in the way of his supposed reasonable theory, we find 

 serious, aye, insurmountable, difficulties opposed to a very metaphysical and visionary 

 idea. 



