236 BRITISH FOSSIL REPTILES. 



to effect more in the way of flight, or be able to raise a larger mass into the air, than 

 could be done by the warm-blooded mammal under an analogous special adaptation. 



When, therefore, the supposed bird's bone, ' Pterosauria,' PI. 4, fig. 4, was first 

 submitted to me by Dr. Buckland, which, on the Pterodactyle hypothesis, could not 

 be the humerus, but must have been one of the smaller bones of the wing, its size 

 seemed decisive against its reference to an animal of flight having a cold-blooded 

 organisation. The subsequent discovery of portions of the skull of the Pterodactyles 

 figured in ib., PI. 3, shows that the manifestations of Creative power in past time 

 surpass the calculations that are founded upon actual nature. 



It is only the practised Comparative Anatomist that can fully realise the difficulty 

 of the attempt to resolve a Palseontological problem from such data as the two 

 fragments of bones first submitted to me in 1840. He alone can adequately appreci- 

 ate the amount of research involved in such a generalization, as that " there is no 

 bird now known, north of the equator, with which the fossils can be compared ;" and 

 when, after a wearying progress through an extensive class, the species is at length 

 found to which the nearest resemblance is made by the fragmentary fossil, and the 

 differences are conscientiously pointed out — as when, e. g., in reference to the humerus 

 of the Albatross, I stated that " it differs therefrom in the more marked angles which 

 bound the three sides," — the genuine worker and searcher after truth may conceive 

 the feelings with which I find myself misrepresented as having " regarded the 

 specimens as belonging to an extinct species of Albatross." My reference of the 

 bones even to the longipennate tribe of natatorial birds, is stated hypothetically, and 

 with due caution. " On the supposition that this fragment of bone is the shaft of 

 the humerus, its length and comparative straightness would prove it to have belonged 

 to one of the longipennate natatorial birds, equalling in size the Albatross," (loc. cit., 

 p. 411.) 



Since the discovery has been made of the manifestly characteristic parts of the 

 genus Pterodacfi/lus, in the Burham Chalk-pit, it has been objected that these bones 

 first discovered there, and described by me as resembhng those of birds of flight, 

 " are so extremely tJiin as to render it most improbable that they could ever have sus- 

 tained such an instrument of flight as the powerful wing of the Albatross or of any 

 other bird : their tenuity is in fact such," says the objector, " as to point out their 

 adaptation to support an expanded membrane, but not pinions."* This assertion 

 needs only for its refutation a simple reference to nature ; sections of the wing- 

 bones of birds may be seen in the Museum of the Royal College of Surgeons, and 

 have been exposed to view, since the discovery of their structure by the founder of 

 that Collection, in every Museum of Comparative Anatomy worthy to be so called. 

 To expose the gratuitous character of the objection above cited, I have selected for 



* Mantell, 'Wonders of Geology,' 1848, vol. i, p. 441. 



