MR. ST. G. MIVART ON THE ANATOMY OF ECHIDNA HYSTRIX. 395 
On the Serial Homology of the Limbs. 
The singular and exceptional conditions presented by certain points in the anatomy of 
the Echidna suggest considerations tending, perhaps, to throw some additional light 
on the serial homology of the fore and hind limbs. 
This particular question of serial homology has for nearly a century past excited in- 
terest and attention. Since 1774 the subject has been more or less noticed or discussed 
by many, e.g. by Vic d’Azyr', Winslow’, Scemmering*, Meckel*, De Blainville’, Bar- 
clay, Gerdy”, Bourgery®, Dugés?, F. Blandin ", Flourens ", Cruveilhier ??, Auzias Tu- 
renne”, Maclise", Owen", Ph. Rigaud, Paul Gervais", Joly and Lavocat'*, Chau- 
veau P, Ch. Martins”, Humphry?!, and Huxley”. 
It appears now to be generally admitted that the scapula, humerus, radius, ulna, 
and pollex are respectively the homotypes, or serial homologues, of the ilium, femur, 
tibia, fibula, and hallux—with more or less divergence of view, however, as regards the 
proximal ends of the ulna and tibia and the sesamoids (or sesamoid-like bones), rarely 
or generally present in the regions of the knee and elbow. The humerus is frequently 
regarded as a bone twisted more or less on its own axis, so that without an actual or 
ideal untwisting, its proximal end will not correspond with the similar extremity of its 
homotype, the femur. 
It also appears to be now generally conceded that the extensor surface and muscles of 
* Histoire de l' Académie des Sciences pour l'année 1774. 
* Exposition Anatomique de la Structure du Corps Humain, nouvelle édition in 12mo, 1775. 
* De corporis humani fabrica, 1794. 
*. Handbuch der menschlichen Anatomie, 1816. 
* Nouveau Dictionnaire d'Histoire Naturelle de Deterville, article Mammifères, t. xix., 1818. 
* Explanations of Mitchel’s Plates of the Bones, 1824. 
" Note sur le parallèle des os (Bulletin Universelle de Férussac, Sciences Médicales, t. xvi., 1829). 
* Traité complet de l' Anatomie de l'Homme, 1832. 
" Mémoires sur la conformité organique de l'échelle animale, 1832. 
” Nouveaux éléments d' Anatomie Descriptive, 1838. 
^ Nouvelles observations sur le parellèle des extrémités dans l'homme et les quadrupèdes (Ann. des Sc. Nat. 1838). 
^ Anatomie descriptive, 1843. 
? Sur les analogies des membres supérieurs avec les inférieurs (Comptes Rendus de l'Acad. des Sc. 1846). ' 
“ Comparative Osteology and the Archetype Skeleton, 1847 ; and in Todd’s Cyclopædia of Anat. and Physiology, 
vol. iv. 1852. 
"= Archetype and Homologies of the Vertebrate Skeleton, 1848 ; and On the Nature of Limbs, Hg. 
" Sur l'homologie des membres supérieurs et inférieurs de l'homme (Comptes Rendus de l'Acad. des Sc. 
1849). 
” Sur la comparaison des membres chez les animaux vertébrés (Ann. des Sc. "iem per ga 
= Etudes d'anatomie philosophique sur le pied et la main de l'homme (Mémoires de l'Académie de Toulouse, 
53). 
2 Traité d’Anatomie comparée des Animaux Domestiques, 1857. 
Nouvelle comparaison des membres pelviens et thoraciques (Ann. des Sc. 
des articulations du coude et du genou (Mémoires de l' Acad. des Sc. de Montpellier, 1862). 
= A Treatise on the Human Skeleton, 1858; and a paper entitled w Observations on the Limbs of Vertebrate 
Animals," 1860, communicated to the Cambridge Philosophical Society. 
= Hunterian Course of Lectures in 1864, reported in the * Medical Times” for that year. 
Nat. 1857) ; and Ostéologie comparée 
