4 IN-TRODrCTORY LECTURE. 



TTe know that it has pleased God to grant us facuhies, by the 

 right use of which we may obtain a true knowledge of His works ; 

 and it seems part of His providence to permit certain parcels of 

 knowledge to be thus introduced from time to time, to the dissipation 

 of the erroneous notions which previously prevailed. By the exer- 

 cise of these faculties, the true shape of our Spheroid was determined, 

 and, after some opposition*, accepted : next, its true relation to the 

 sun, as respects its motion. It has been reserved for the present 

 generation to acquire more just ideas of the age of the world, and 

 Anatomy has been, and must be, the chief and most essential means 

 of estabhshing this important element in the earth's history. 



But Anatomy aids not only the Geologist, but the Geographer : by 

 comparing the local distribution of restored extinct species from 

 coeval geological strata over all the earth, with the geographical dis- 

 tribution of existing animals, we obtain an insight into the past con- 

 ditions of continents and islands ; we determine that our own island, 

 for example, once formed part of the continent, and obtain data for 

 tracing out much greater mutations and alternations of land and 

 sea. t 



Thus, upon Anatomy depends the safe and successful practice of 

 Medicine and Surgery : the knowledge of the uses of parts, and of 

 their essential nature in Man, viewed as modifications of a general 

 type. Anatomy is the basis of right classification and philosophical 

 Zoology : it unfolds the law of the introduction of animal life on this 

 planet : it is essential to the right progress of Geology, and gives 

 an insight into the true chronology and ancient geography of the 

 globe. 



Almost every day brings some new proof of the importance of the 

 knowledge of Animal Organisation, which bids fair to take rank as the 

 first of all sciences ; and it is to Anatomy, that we have the high 

 privilege to be introduced at the very outset of our professional 

 studies. 



More might be said, and better, in praise of our peculiar science ; 

 but when I reflect on that department which I propose to treat of 

 in the present Lectures, viz. the Comparative Anatomy of the Ver- 

 tebrate Classes of Animals, its great extent, and the diversity of 

 details which it embraces, I feel it incumbent to enter, without fur- 

 ther preface, upon the proper subject of this Course. 



* See Lactantius, Instit. lib. iii. c. 24, against the earth's rotundity . and Augus- 

 tine, De Chit. Dei, lib. xvi. c. 9. against Antipodes. 



t Report of British Association for the Advancement of Science, 1844; and 

 " History of British Fossil Mammalia," 8vo. 1845, pp. xxvii. slvi. 



