176 REPORT—1846, 
they must be distinguished by different special names according to their par- 
ticular modifications in the same skeleton, as e. g. mandible, coracoid, ilium, 
&ce., I call such serially related or repeated parts ‘homotypes.’ The basi- 
occipital is the homotype of the basi-sphenoid ; or in other words, when the 
basi-occipital is said to repeat in its vertebra or natural segment of the ske- 
leton the basi-sphenoid or body of the parietal vertebra, or the bodies of the 
atlas and succeeding vertebra, its serial homology is indicated. The study 
of this kind of homologies was commenced by Vicq d’Azyr, in his ingenious 
memoir ‘On the Parallelism of the Fore and Hind Limbs.’ If we except 
the complex and extremely diversified and modified parts of the radiated 
appendages of the vertebral segments, to which Vicq d’Azyr restricted his 
comparisons, the serial homologies of the skeleton are necessarily demon- 
strated when the general and special homologies have been determined. 
In the present section of this Report I propose to consider some of those 
examples of special homology which are least satisfactorily determined and 
respecting which different opinions still sway different anatomists. Such 
instances are fortunately few, thanks to the persevering and successful labours 
of the great comparative anatomists of the last half-century: pre-eminent 
amongst whom will ever stand the name of Cuvier, in whose classical works, 
‘ Ossemens Fossiles,’ ‘Histoire des Poissons,’ ‘ Lecons d’ Anatomie Comparée’ 
(posthumous edition), and ‘ Régne Animal,’ 1828, will be found the richest 
illustrations of the special homological relations of the bones in the four classes 
of vertebrate animals. 
Second only to Cuvier must be named Georrroy St. H1Laire, whose 
memoir on the Bones of the Skull in Birdsascompared with those in Mammals, 
in the ‘ Annales du Muséum, t. x. (1807), forms an early and brilliant example 
of the quest of special homologies, which could not fail, with other and similar 
investigations of the same ingenious author, to impart a stimulus to that 
philosophical department of anatomical inquiry*. In regard to the osteology 
of the crocodile, we find Cuvier and Geoffroy engaged in a long parallel series 
of rival researches, the results of which have had the happiest effects in de- 
termining some of the most difficult questions of special homology. 
Nor was the co-operation of zealous cultivators of comparative anatomy 
wanting in the eminent schools and universities of Germany. GOETHE, in- 
deed, had taken the lead in inquiries of this nature in his determination, in 1787, 
of the special homology of that anterior part of the human upper maxillary 
bone which is separated by a more or less extensive suture from the rest of 
the bone in the foetus; and the philosophical principles propounded in the 
great poet's famous anatomical essays called forth the valuable labours of the 
kindred spirits, Oken, Bosanus, MrecxeL, Carus, and other eminent culti- 
vators of anatomical philosophy in Germany. 
It is not requisite for the purpose I have in view, to trace step by step the 
progress of the special homological department of anatomy. Its present 
state, as regards the skull of the Vertebrata, will be best exposed by the sub- 
joined tabular view of the fruits of the latest inquiries. 
TasLE I. (See end of the Report.) 
This table gives at one view the general results of the researches into 
the conformity of structure of the skull throughout the vertebrate series, 
* Oken’s famous ‘“ Programm, Uber die Bedeutung der Schadelknochen” was published 
in the same year (1807) as Geoffroy’s Memoir on the Bird’s skull; but it is devoted less to 
the determination of ‘ special’ than of ‘ general homologies’: it has, in fact, a much higher 
aim than the contemporary publication of the French anatomist, in which we seek in vain 
for any glimpse of those higher relations of the bones of the skull, the discovery of which 
has conferred immortality on the name of OKEN. 
