33. Lynx canadensis Raf. CANADA LYNX.-" Reputed to be not uncommon."-R.

"The Panther (Felis concolor) is said to occur, but no satisfactory evidence of its present existence in the region was obtained."-R.

Article IV.-ON THE SEASONAL CHANGE OF COLOR IN THE VARYING HARE (LEPUS AMERICANUS ERXL.).

By J. A. ALLEN..

INTRODUCTORY.

Any one at all familiar with the seasonal changes of color in mammals, and also with the periodic shedding and renewal of the pelage, cannot have failed to note the coincidence of the two phenomena. As a rule, particularly among the Rodentia, the change becomes first apparent on the feet and about the nose, extending gradually up the limbs and over the head, and from the base of the tail anteriorly, and from the sides of the body toward the median line. This, perhaps, may be assumed to be the usual method, particularly in the spring molt, but the process is subject to much irregularity, even among individuals of the same species, and it seems to vary somewhat in different groups. Late in spring, usually at the close of the breeding season, the old coat has become worn, faded, and more or less ragged, and the new hair may be seen coming in irregularly in patches, in addition to the more symmetrical method of change already indicated.

The new hair, forming the summer coat, is much shorter and thinner, and usually brighter in color than the coat it replaces. The change from this coat to the winter dress again is generally accomplished more or less insidiously, but apparently in much the same order as in the case of the change from the winter to the summer coat. The summer coat is worn usually for a much shorter period, and fails to show the same amount of wear and fading, so that the transition is generally less marked and abrupt; the new hair comes in gradually, and overtops the short summer coat, which apparently falls out as the new hair becomes more abundant and longer. Only in the case of some more or less radical change in color can the progress of the fall molt be readily traced,

Thus in the Hares, as will be shown later, it is quite different from what it is in the Squirrels.

as in the Varying Hares, forming the subject of the present article. In these a brown summer pelage is replaced by a white winter coat; and the change is thus so radical that it should seemingly be an easy matter to determine how it is produced. Yet just how the change of color is effected is still to some extent a matter of dispute. While supposed to be largely due to a molt, it sometimes appears to take place so suddenly that it is popularly thought to be due, in some degree at least, to the blanching of the summer hair.

CHARACTER OF THE PELAGE.

In order to understand fully the remarks that follow, it is necessary to briefly describe the summer and the winter pelage.

Summer Pelage.-The general color of the upper parts, including the limbs externally, varies in different individuals from pale yellowish gray to deep yellowish brown, and even occasionally to reddish brown, more or less varied with blackish, particularly over the middle and posterior part of the back, due in part to most of the hairs being tipped with black, but often mainly to a strong sprinkling of wholly deep black hairs. There is also a broad pectoral band or 'ruff,' varying from two to three inches in breadth, and in color from yellowish gray to deep rusty fawn. The rest of the lower surface, including the chin and throat, a part of the inner side of the hind limbs, and the whole of the ventral surface posterior to the breast, is white, often washed slightly with fulvous or grayish. The ears are brownish, more or less rusty, the extreme edge whitish, particularly on the posterior border, the apical third externally with a submargin of black, expanding towards the tip into a broad blackish subapical spot. Except basally and along the anterior border, the ears are thinly haired The soles of the feet are generally more or less dusky.

throughout.

This pelage, considered in detail, consists of two distinct partsa thick woolly underfur, and a heavy coat of long overhair. The underfur is plumbeous basally, generally for about two-thirds of its length, with the apical third fulvous or tawny, the exact shade varying in different individuals.

The overhair is of two kinds, as regards both pattern of color and structure. It consists principally of particolored hairs, which are plumbeous basally, generally about as far as the plumbeous zone of the underfur, then blackish for about one-half their total length, then passing abruptly into a broad band of fulvous, and then again abruptly into black at the extreme tip. These hairs

are extremely attenuated at the base, gradually thicken as they become black, attaining their greatest diameter at and throughout the subapical fulvous zone, and then rapidly taper to a finepointed tip. Mingled with these particolored hairs is a greater or less profusion of wholly black, rather longer hairs, of coarser and firmer texture. These hairs vary greatly in abundance in different individuals, and over different parts of the body, being most abundant along the middle and posterior part of the back. They taper slightly towards the base and tip, but are of a much more uniform diameter than are the particolored hairs. They overtop the particolored hairs, thus not only greatly increasing the blackish cast of the dorsal surface, but by their rigidity imparting greater firmness to the surface of the pelage.

During the autumnal change the particolored hairs are the first to fall out; the longer, firmer, wholly black hairs persist later, quite a proportion of them often remaining after the particolored hairs have disappeared, giving a more or less leaden or dingy effect to the otherwise white winter coat. This effect gradually passes away, although a few black hairs can be found in most early December specimens, but they generally wholly disappear by the middle or during the last half of the month, excepting at southern localities.

Winter Pelage.-Generally everywhere white at the surface, except the tips and edges of the ears, and the soles of the feet, although the latter are much lighter in color than in summer.

The winter pelage is, of course, also made up of two kinds of hair-a woolly underfur, rather longer and much more abundant than in summer, and the longer, coarser, firmer overhair. The underfur is colored much as in summer, except that the tips of the longer fibres are pure white, like the overhair. The overhair is almost invariably pure white from base to tip, although the extreme basal portions of some of the hairs are grayish and pass into a horn-gray middle zone. This condition is rare, occurring in comparatively few specimens, and then only in a very small percentage of the hairs making up the long white coat of overhair. The hairs composing the white covering of overhair vary greatly in diameter, not only in different individuals, but in

different parts of the body of the same animal, and even from the same region, as from the middle of the back. The coarser hairs have a firm shaft from the tip to the point of insertion into the skin; the finer hairs have only the outer half or two-thirds firm and shaftlike, the lower portion dwindling to a thin filament, and when detached is curly and not unlike one of the coarser fibres of underfur. There is indeed, in some individuals, an almost complete intergradation as regards texture between the coarser overhair and the longer white-tipped filaments of underfur.

MATERIAL EXAMINED.

The following observations are based on a series of about 75 specimens, nearly all of which belong to the Museum Collection.' The greater part have been collected for the express purpose of this investigation, and include specimens taken through both the autumnal and vernal changes, as well as at other seasons. About thirty were collected near Andover, New Brunswick, during October, November and December (Oct. 27-Dec. 14), 1894, for the purpose of securing a series showing the transition from the brown summer coat to the white dress of winter. A part of this series was obtained by Mr. J. Rowley, Jr., and his associates, on the recent Museum Expedition to New Brunswick (see antea, pp. 99 and 101), and the rest were secured later from an Indian hunter through Mr. Rowley's agency. The greater part of the rest of the series is from the vicinity of Rutland, Vermont, taken at various intervals from Oct. 17 to April 15, and for which I am mainly indebted to Mr. W. W. Granger, who has also kindly secured a series, collected at intervals during March and April, to illustrate the spring molt. There are also four specimens from Kittson County, Minn. (Nov. 17-22), collected and presented by Dr. E. A. Mearns.

This material shows that there is considerable individual variation in respect to the exact time of change at the same locality. Thus some of the specimens taken as early as Nov. 17, both

1 I am indebted to Dr. C. Hart Merriam, of Washington, for the loan of 13 specimens from his own collection, which have proved especially useful in the present connection. Six of them are from the Adirondack region of New York, and seven from Elk River, Minn. The former include specimens taken in summer and autumn, while the latter were taken during the spring molt.