THE ANCESTRY OF DOMESTICATED CATTLE. 
211 
the result of natural selection as in the case of wild animals in a 
region of snow and ice. Polled cattle are also found in the lake 
dwellings and hence have been among the early forms domesticated. 
Again, polled cattle are notoriously prepotent in transmitting this 
characteristic when crossed with horned cattle. In the struggle for 
existence polled individuals would be less likely to survive than those 
with horns, but under domestication would be protected. Thus, 
Arenander supposes that horned individuals occurred by spontaneous 
variation and were preserved by natural selection and that polled 
individuals which occur are reversions. 
Arenander (1898) is criticized by Keller (1899), who says that thei 
remains of hornless cattle found in the lake dwellings are in the 
later ones, while according to Arenander it should be the reverse. 
Hehn and Middendorf (1888) think the polled breeds of the north 
came about because the Scythians wandered farther and farther to 
the north and took their polled cattle with them. This is stoutly de- 
nied by Werner (1902) who thinks the migration of people as well 
as of cattle was to the south instead of toward the north. 
In the Upper Eocene and Lower Miocene the generalized form of 
deer and antelopes was polled and their associates were tuskless 
swine and rhinoceroses (Auld, 1887). In the Upper Miocene the 
antlers of deer were small. Darw^in quotes a graduated series of 
antelopes from the polled condition. The pronghorn as we have seen 
is an intermediate between the deciduous solid-horned and the non- 
deciduous hollow-horned forms (Gadow). Hence it may be that the 
horned condition was not reached until the primitive form of deer, 
antelope, and cattle had differentiated into forms closely conforming 
to the present tjqoes. That the cows of the oldest member of *the 
cattle kind, Bos eJatus, were without horns lends support to this 
view. According to Forsyth-Major, the hornless skulls from the 
Tertiary deposits of the Val d'Arno in Italy are females of the sub- 
genus Leptolos (Bos elatus Pomel). Until earlier representatives 
of the genus are found we must consider the oldest European forms 
of cattle as having polled females, an indication that in still older 
species both sexes were without horns. 
Ewart (1909), after reviewing the various theories of the occa- 
sional appearance of hornless cattle, expresses the view that domes- 
tication and the unfavorable conditions which are thought to have 
reduced Bos taurus in size may also have led to the hornless condi- 
tion. Recent explorations in Turkestan and records from Babylonia 
lend support to this view, i. e., that the appearance of the polled 
character is a reversion to the ancestral hornless type. 
In a recent paper (Scientific Proceedings, Royal Dublin Society, 
vol. 12, No. 15, June, 1909), Prof. James Vilson, of the Royal 
lege of Science, Dublin, attempts to show that the hornless breeds of 
