£04 PALAEONTOLOGY. 



been treated of, tracing their modifications from the most simple to the 

 most complex forms, agreeably with the order of arrangement of the first 

 division of the Hunterian Physiological Series, in the lectures which 

 occupied the first five years of my office as Hunterian Professor. 



Afterwards I made the generation of animals and the development 

 of the different organs, the subject of two Courses of Lectures, and illus- 

 trated them by the preparations of the second division of the Hunterian 

 Physiological Series. 



In next entering upon the illustration of the extensive collection of 

 Comparative Osteology, I felt it to be my duty to go as deeply and 

 thoroughly as my powers and leisure would enable me, into the question 

 which the two great luminaries of the School of Anatomy and Natural 

 History of France, Cuvier and Geoffroy St. Hilaire, had left undecided, 

 in the ardent discussions which agitated the close of their respective 

 careers : I allude to the subject, or line of zootomical research, which 

 is commonly called abroad • Philosophical Anatomy,' but which is, in 

 truth, ' Homological Anatomy,' or that which aims at determining the 

 strictly answerable parts and organs in different species, and which 

 expresses the successful results of such comparisons, by giving to the 

 demonstrably answerable parts and organs in different animals the same 

 name. The aggregate results of this fifth way of anatomical research, 

 exemplify the extent to which the term ' Unity of Organization ' can 

 be applied to the animal kingdom, and they show the kind and amount 

 of truth which was partly appreciated by Goethe, Oken, Spix, and 

 Cams, but was obscured by the figurative and commonly exaggerated 

 expressions by which those gifted and accomplished intellects endea- 

 voured to express a great and pregnant truth of which they had ob- 

 tained different partial views. 



After this Session, as I have never deemed it the privilege of your 

 Hunterian Professor to repose upon the repetition of the same annual 

 course of lectures, with the mere addition of the chief discoveries of the 

 preceding year, I entered upon the study of the Hunterian Series of 

 entire animals of which the Catalogue of the Invertebrated Classes has 

 been published, and arranged the facts of comparative anatomy according 

 to their correlations in subserviency to the habits of particular species. 



In the session of last year I concluded the series of lectures in which 

 the animal organization was treated of according to the classes of ani- 

 mals, beginning with the lowest and ending with the highest. 



I still look forward to the kind and liberal indulgence of the Council 

 of this College for the license, if life and health be spared, to reduce 

 and make public the manifold materials which I have accumulated for 

 these several courses of Hunterian Lectures. 



