Hybridity in Animals. 39 
vania, of the occurrence of fossil foot-prints of a large reptilian, 
in the middle of the ancient coal-measures. They project, in 
relief, from the lower surfaces of slabs of sandstone; and are 
also found impressed on the subjacent layers of fine unctuous 
clay. ‘This is the first well-established example of a vertebrated 
animal, more highly organized than fishes, being met with in a 
stratum of such high antiquity. 
Art. V.—Hypbridity in Animals, considered in reference to the 
question of the Unity of the Human Species; by Samvet 
Grorce Morron, M. D.* 
(Read before the Academy of Nat. Sci. of Philadelphia, Nov. 4 and 11, 1846.) 
7 Parr I. 
Introductory Remarks. 
Te facts connected with hybridity in the inferior classes of 
animals, have an important bearing on one of the most interesting 
hus 
hybridity the test of specific character. It follows, according to 
- i‘ aa ‘ i | € V a 7 
species, the intermixture of these would go no further than to 
produce a sterile hybrid variety. But since all the races are ca- 
pable of producing, with each other, a progeny more or less fer- 
tile, it is inferred that they must all belong to one and the same 
species. This is the question at issue. 
It may, at first view, appear superfluous to go over the whole 
ground of inquiry ; but apart from its Ethnographic relations, it 
is my wish to call attention to a branch of science that has hith- 
erto been singularly neglected, and perhaps more so than any 
other. Having sought in vain for some collective exposition of 
its details, I was at length induced to examine them for myself; 
d in now giving them publicity, I respectfully solicit, from 
“In receiving this paper, we commit ourselves (as in other cases) to none of 
the opinions of the pon We may add, that we have no fear of discussion on 
any pointin science. Facts are the markings of a Divine hand around and within 
“us, and when studied in ail their bearings, they lead in the end to the establish- 
ment of Truth.—£ds. Re . 
t Dr. James Cowles Prichard, the first Ethnographer of this or any age, has, with 
great care and candor, collected many of the Howing examples of hybridity, al- 
oug! to my view, they conflict strongly with his main position.—See Researches 
into the Physical History of Mankind, yol. i. 
