44 Mamm. 
MAMMALIA. 
shows that the proportion of male foals born increases in proportion to 
the greater age of the parents, especially of the father. 
4 Pietremont, C. A. Les Chevaux dans les temps pr6historiques and 
historiques. Paris: 1883, 8vo, pp. 776. 
A complete account of the history of the domestic horse, as known 
from its fossil remains and from early traditions and documents. 
\Isteglich, B. Ueber den Mechanismus des Pferdehufes mit besonderer 
Beriicksichtigung der Hufrotationstheorie des Prof. Dr. Lechner in 
Wien. Inaug. diss. Leipzig : 1883, 8vo. 
[Not seen by Recorder ; cf. Zool. Anz. vi. p. 545.] 
^ Wortman, J. L. On the Origin of the Horse. Rev. Sci. xxxi. 
pp. 705-714 (with figure). 
. Recent Discoveries of Fossil Horses. J. Comp. Med. iii. p. 281. 
A general account of the fossil Equidce discovered in North America, 
with figures of limb-bones. 
^ Equidce. A popular demonstration of their geological history is given 
by W. H. Flower, P. Geol. Ass. viii. p. 114. 
Equus: On its extinction in America during Pliocene times ; S. Gar- 
man, P. Bost. Soc. xxii. p. 252.*^ On osteological differences between 
horses, asses, and mules ; J. Arloing, Bull. Soc. d’Anthrop. Lyon, 1883 
[not seen by Recorder; cf Zool. Anz. vii. p. 155]. 
Equus caballus. On its teeth and their diseases ; R. Jennings, J. Comp. 
Med. iii. pp. 143 & 288, & iv. p. 121. 4 Ou the nomenclature of the 
arteries of its brain ; J. Tereg, JB. Thierarzneisch. Hannover, xv. 
1882-3, p. 26 [not seen by Recorder ; cf. Zool. Anz. vii. p. 155]. On 
its colour in different countries ; Langkavel, Zool. Gart. xxiv. p. 38. 
The evolution of the American trotting-horse ; W. H. Brewer, Am. J. 
Sci. (3) xxv. p. 299. Its continued progress mathematically calculated ; 
F. E. Nepher, op. cit. (3) xxvi. pp. 20 & 86 ; W. H. Pickering, tom. cit. 
p. 378. An interesting series of papers, showing how the interest taken 
in trotting- horses has led to their gradual improvement in pace from 
3 min. for the mile in 1818 to 2 min. lO^ sec. at the present time, 
si Equus caballus. A. Nehring, from the evidence furnished by the nu- 
merous fossil remains found during the last ten years in Germany, believes 
that the horse, far from being, as is usually stated, an animal introduced 
from Asia, is a wholly indigenous European species, and that it has ex- 
isted in Central Europe “ continuously from the beginning of the Diluvial 
Period to the present time.’' He states that, during most of the early 
Diluvial Period, especially during the Glacial Epoch, a great part of Central 
Europe was covered with open steppe-land, where horses, identical with 
the present animal, flourished in great numbers ; that then, as the forests 
grew and the open lands became restricted in extent, the horses became 
reduced both in number and size, the latter being also owing to their 
increasing domestication by savage races of men, who would have over- 
worked and otherwise ill-treated them ; and that, finally, as man became 
more civilized, and learnt to treat his animals better, the horses, by this 
