SOME EARLY MAMMALS 241 
horses, which roam in such vast herds on the Pampas, are not 
the descendants of the fossil horse of South America, but have 
sprung from those introduced by the Spaniards more than three 
hundred years ago. 
A great deal of fresh material has been collected since the 
present writer, in the year 1894, published, in his Creatures of 
Other Days, some account of the evolution of the horse as told 
by the late Professors Marsh and Cope, and others; and some 
of the old conclusions have to be abandoned. Professor H. F. 
Osborn,! of the American Museum of Natural History, has taken 
up this line of research, and obtained important results. One 
of the trustees of the above museum, the late Mr. W. C. Whitney, 
generously provided funds for explorations. These expeditions 
began in the year 1890, and up to the year 1904, the American 
Museum Collection has been enriched by the more or less com- 
plete remains of 771 fossil horses, of which 146 were secured by 
Mr. J. W. Gidley, who took up this work under Professor 
Osborn. Five complete skeletons are now to be seen mounted 
in the above museum. All the other museums of the world 
together have only three complete mounted skeletons, and from all 
this wealth of material Professor Osborn has been able to find 
out three or four collateral lines of descent, some of which are 
mixed up with the pedigree published years ago by the late 
Professor Marsh. 
According to Professor Osborn the line of evolution of the 
horse is, very briefly, as follows:—First we have the little 
Eohippus (or “dawn horse”) only eleven inches (or two and 
three-tenths hands) at the withers, with its wrist or knee near 
the ground. The hand was still short, with four little hoofs, 
1 See his article in the Century Magazine for November, 1904, on the 
evolution of the horse in America (illustrated), 
R 
