§ 10. FOSSIL MAMMALIAN REMAINS. 137 



lenreuth, Kirkdale, Kent's Hole near Torquay, &c. are 

 examples. 



Lastly. Osseous breccias that occur in fissures of lime- 

 stone on the shores of the Mediterranean, in the Ionian 

 Isles, in the rock of Gibraltar, at Plymouth, in the Mendip 

 hills, &c * 



Before directing your attention to the fossils before us, 

 which are from alluvial deposits of various ages and from 

 different localities, it will be necessary to review the leading 

 principles of the science which treats of the structure of 

 organized beings. Thus while in the preceding lecture we 

 referred to Astronomy to dissipate the obscurity which 

 shrouded the earliest physical condition of our planet, we 

 are now led to that important department of natural 

 knowledge termed Comparative Anatomy, to enable us to 

 determine the extinct forms of animal existence. I shall 

 therefore explain the mode of induction employed by the 

 scientific observer in the investigation of the fossil remains 

 of animals, and by which he is enabled to ascertain the 

 structure and economy of creatures, which have long since 

 disappeared from the face of the earth. 



11. Comparative anatomy. — To a person uninstructed 

 in anatomical details, the specimens before us would appear 

 a confused medley of bones, and of osseous fragments im- 

 pacted in solid stone ; and the only knowledge he could 

 derive from their examination would be the fact, that the 

 stone was once in the state of sand or mud, in which, 

 while soft, the bones had become imbedded. But in vain 

 would he seek for further information from these precious 

 historical monuments of Nature ; to him they would prove 

 as unintelligible as were the hieroglyphics of Egypt, before 

 Young and Champollion explained their mysterious import. 

 It is only by an acquaintance with the structure of the living 



* Dr. Buckland's Bridgwater Essay, p. 94. 



