JACKSON — A HYBRID DEER 
143 
The hybrid specimen is not strictly intermediate in characters be- 
tween hemionus and columhianus. In some characters it is indistin- 
guishable from hemionus, in another like typical columhianus, and in 
one respect it appears to be intermediate. On the whole it is more like 
. hemionus than hke columhianus. The hybrid was a large deer and, 
in size, would pass for a rather large hemionus. It also has the large 
ears characteristic of the mule deer. The metatarsal gland on the left 
leg measures, in the tanned skin, 125 mm., that on the right leg 119 
mm., in every respect typical glands of full blood hemionus. The 
antlers also are indistinguishable from those of the mule deer. They 
are not as long as some mule deer antlers, but have as heavy beams as 
any I have examined, and branch in a fairly normal mule-deer fashion. 
The tail, however, is distinctly and unmistakably hke that of a black- 
tailed deer. The post-frontal region of the skull appears to be inter- 
mediate between that of a black-tailed deer and that of a mule deer, 
but probably is nearer that of the black-tail. Viewed in life then, 
this animal undoubtedly had the appearance of a mule deer with a 
black-tailed deer’s tail. 
CONCLUSIONS 
It is to be admitted that from a geneticist’s point of view this paper 
is not entirely satisfactory and that a more serious study of the specimen 
might bring out many additional facts. However, three points are 
worthy of notice. Regardless of variance of opinions as to the defini- 
tions of a species and a subspecies, so far as I am aware it has been 
conceded by all mammalogists that the mule deer and the black- 
tailed deer are distinct species. The first point, then, is that within 
a certain area in the state of Washington two distinct species, the mule 
deer and the black-tailed deer, interbreed in their native habitat. Second, 
the hybrids of the first filial generation produced by the crossing of these 
two distinct species are fertile to each other. Third, it is strongly sug- 
gested that in these crosses certain unit characters aro transmitted to the 
offspring. The hybrid studied was essentially a mule deer in several 
characters, black-tailed deer in at least one character, and showed 
a possible tendency to be intermediate in one. Whether these charac- 
ters are transmitted in Mendelian ratio is, of course, impossible to de- 
termine with the material at hand. 
U, S. Biological Survey, Washington, D. C. 
