IN THE LIMBS OF MAMMALIA. 67 



celebrated anatomists, such as Vicq d'Azyr, Soemmering, Goethe, Meckel, deBlainville, 

 Barclay, Gerdy, Blandin, Bourgery and Cruveilhier, Turenne, Flourens, Owen, and more 

 recently, Mons. Chas. Martins, Professor of Medical Natural History of the Faculty of Medi- 

 cine of Montpellier, in a paper entitled, " Nouvelle comparaison des membres pelviens et 

 thoraciques chez l'homme et chez les mammiferes deduite de la torsion de l'hurnerus," 

 (Annales des Sciences Naturelles, tome viii. p. 45, 1857.) And again in 1862, in a second 

 paper entitled, " Memoire sur l'osteologie comparee des articulations du coude et du genou 

 chez les mammiferes les oiseaux et les reptiles." 



In the former, after discussing and objecting to the views of the other anatomists above 

 named, he says on page 55 : — 



" To recapitulate, these comparisons (paralleles) of the superior and inferior extremities 

 of vertebrates may be reduced to three : 



1st. The hypothesis of Vicq d'Azyr, who compares the superior member of one side with 

 the inferior member of the other side. (Plate ii, figs. 1 and 3.) 



2d. The detailed (detaille) comparison of Bourgery, who combines the hypothesis of 

 Vicq d'Azyr, with a crossing, in virtue of which the head of the tibia represents the ulna, its 

 lower extremity the radius, while the femoral extremity of the fibula corresponds with the 

 radius, and its tarsal extremity with the ulna. 



3d. The explanation of Flourens, where the pelvic member of one side is assimilated 

 with the thoracic member of the same side, the fore-arm being in a state of pronation." 



We may easily see, as Mons. Martins has shown, that each of these comparisons is open to 

 serious objections, while their discordance is such that even at this late clay those anatomists 

 who do not utterly discredit the existence of any natural relation between the fore and 

 hind limbs " are in doubt between them, without being able to agree upon the most impor- 

 tant point, namely, the identification of the two bones of the fore-arm with those of 

 the leg." 



It will be noted that through all these comparisons runs the effort to demonstrate a 

 parallelism between the anterior and posterior extremities, and not one of the anatomists 

 who advocate them seems to have appreciated the significance of Oken's a priori assertion 

 of an oppositeness or symmetry between the two ends of the vertebrate body, which gen- 

 eralization he simply did not extend to the limbs, the diverging appendages of these two 

 regions. 



That this oppositeness or symmetry does really exist, has I hope been already shown in this 

 paper, and I desire to repeat here that the first suggestion of the idea to me came from my 

 illustrious instructor in anatomy, the Hersey Professor of Anatomy in Harvard University, 

 from whom, much rather than from myself, would I prefer that others should learn what 

 has afforded me so much mental pleasure and profit. 1 



Mons. Martins' view is in his own words, as follows : " The humerus is a bone 

 twisted on its axis 180 degrees. The femur is straight without twisting. The humerus 

 being a twisted femur, if we would compare the two bones, we must first untwist the 

 humerus." 



In other words, having made up his mind that the limbs are parallel, and finding that 

 they are not parallel, he makes them so by a process of untwisting, to which I hope, others 

 will perceive obstacles both mental and physical. 



1 See a short communication by Professor J. Wyman to the ceeding sof B. S. N. II., vol. vii., p. 317, " on anterior and 

 Boston Society of Natural History for June 6th, 1860. Pro- posterior symmetry in the limbs of mammals." 



