Prof. Owen’s Letter to Prof. Silliman. —=———-185 
first observer, and to Prof. Hitchcock as the successful investiga- 
tor of this important branch of paleontology, confessed that the 
gigantic bones from New Zealand, evincing as they did most 
unequivocally the existence, even in our own times, of birds as 
large as any required by the American footmarks, had removed 
his scepticism, and that he had no hesitation in declaring his be- 
lief that the Ornithichnites have been produced by the imprints 
of the feet of birds which had walked over the rock when in a 
soft and impressible state ; an opinion in which I entirely concur. 
Sooner or later the skeletons of these unknown birds will be dis- 
covered in the strata. 
It cannot fail, sir, to be gratifying to you to know, that your 
brief but lucid description, illustrated by the highly interesting 
suite of specimens, has placed this important subject before the 
geologists of England in a most clear and satisfactory point of 
view, and that the thanks of the Society were warmly and unan- 
imously expressed for so valuable acommunication. With great 
respect, I am, dear sir, your obliged and faithful servant, 
Gipron Atcernon MAnreELt. 
Letter of Prof. Owen to Prof. Silliman on the Ornithichnites 
and Dinornis. 
Royal College of Surgeons, London, March 16th, 1843. 
My dear Sir—I beg to acknowledge the favor of your esteem- 
ed letter of the 27th of February, and am unwilling to delay my 
answer, although I am not able to answer all the points to which 
it relates. Ihave not yet, for example, seen the entire collection 
of foot-prints in the possession of our common friend, Dr. Man- 
tell, but on the few which he has obligingly submitted to me, 
(ewer very clear ones last Saturday night at the soirée of the Pres- 
ident of the Royal Society,) I may venture, after much mature 
consideration, to speak. “You may be aware that M. De Blain- 
ville contends that the ground—viz. a single bone or articular 
facet of a bone—on which Cuvier deemed it possible to recon- 
struct the entire animal, is inadequate to that end. In this opin- 
ion I do not coincide. Ihave had too frequent evidence of the 
potency of the law of correlation of structures in an animal or- 
ganism to doubt the strength of Cuvier’s proposition. But if a 
single bone has been deemed insufficient to give the entire ani- 
mal, with more reason may we doubt the efficacy of a foot-print. 
Vol. xrv, No. 1.—April-June, 1843. 24 
