erable to that subspecies.

Intergradation, then, occurs between _L. intermedius_ and _L.
floridanus_ in some degree in southern Louisiana and in more marked
degree in southeastern Texas. Specimens from the area of intergradation
vary more individually in many features than do specimens from other
areas. In general the intergrades tend to resemble _floridanus_ in
small size externally and _intermedius_ in large size of skull. The
specimens from southeastern Texas differ from typical specimens of both
subspecies in color, being pale yellowish-gray (instead of yellowish to
yellowish-orange as in _intermedius_ or yellowish brown to
brownish-gray as in _floridanus_), and this difference is shared to
some extent with animals from Louisiana, the latter being somewhat
intermediate between bats from Texas and those from Florida and
Georgia, although nearer those from Florida and Georgia.

An hypothesis to account for the variation noted is that in Wisconsin
Time, and perhaps in earlier Pleistocene times, this yellow bat was (as
it is now) a warmth-adapted animal as Blair (1959:461) would term it.
Some cool period forced the mainland populations of the two species
into two refugia--peninsular Florida and eastern Mexico--and the
present area of intergradation is, therefore, of a secondary rather
than a primary type. Possibly also the relatively treeless area of part
of southern Texas has made for a sparse population there of _Lasiurus
intermedius_ and gene flow now may be, and long may have been, slight
between the eastern and southern segments of the species.

It could be contended that the peculiar coloration of specimens from
southeastern Texas, coupled with the tendency to have a large skull (as
has _intermedius_) and small external dimensions (as has _floridanus_),
justifies subspecific recognition for the animals that here are termed
intergrades. But, judging by the specimens now available, such
subspecific recognition would tend to obscure rather than clarify the
geographic variation noted.

_Life History_

Probably bats of the species _Lasiurus intermedius_ seek retreats
primarily in trees (see Moore, 1949_a_:59-60) but Baker and Dickerman
(1956:443) reported "approximately 45 yellow bats" concealed on July
22, 1955, "among dried corn stalks hanging from the sides of a large
open tobacco shed" in the state of Veracruz. Young are born in late
spring, three being the only number known except that Davis (1960:59)
was