lumbeous, just the color of the dark
underfur of the adult, or a shade darker, while the characteristic white
markings of the adult stood out sharply as pinkish-white areas against
the dark background (see Pl. IX, Fig. 2, at p. 32). The proportions were
much as in the adult, except that the tails were relatively much shorter
and the feet relatively longer.

Only one other record of young is at hand, that by Bailey, who secured
the young after capture of a suckling female at Santa Rosa, N. Mex. In
this case the litter contained only one. This was squeaking when found,
but was not large enough to crawl away. Its eyes and ears were closed,
and its soft, naked skin was distinctly marked with the pattern of the
adult, the colors being as given for the other two. This juvenile lived
only a week. Young less than half grown were not trapped or noted in our
poisoning operations outside the dens.

Kangaroo rats, if _spectabilis_ be representative, reproduce at a slow
rate as compared with many other small rodents. We have records of 67
females with embryos or scars showing the number produced, and of the
two litters of young described above. Of the 69 females thus recorded,
15, or 21.7 per cent, had but one offspring each; 52, or 75.3 per cent,
but two each; while only 2 individuals, or 2.9 per cent, had three.
Three young is the maximum litter recorded. This, taken in connection
with the protracted breeding season and lack of sure evidence of the
production of two broods a year, gives a surprisingly low rate of
reproduction, indicating relative freedom from inimical factors.

Our breeding records for _merriami_ are fewer than for _spectabilis_,
but are very similar in every way so far as they go, both as to the time
of year and number of young.

FOOD AND STORAGE.

_Dipodomys s. spectabilis_ does not hibernate, so must prepare for
unfavorable seasons by extensive storage of food materials. There are
two seasons of the year, in southeastern Arizona at least, when storage
of food takes place, namely, in spring, during April or May, and in
fall, from September to November, the latter being the more important.
For the periods between, the animal must rely largely on stored
materials. Not infrequently a season of severe drought precludes the
possibility of any storage. The summer and fall of 1918 was such a
season on the Range Reserve (Pl. II, Fig. 2). If food stores are
inadequate at such a time the kangaroo rats must pe