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Show 1869.] MR. F. H. WELCH ON LEPUS AMERICANUS. 231 on an equality with the pile of the autumnal coat on the sides, forming a mottled whity-brown band from ears to tail, contrasting strongly with the centre of the back, at present comparatively unchanged; anon they outstrip this, reducing the mottling on the sides to a pure white, and, gradually implicating the centre of the back in the same process (through the varying hue-phases, according as the rapidly advancing white growth appears through and finally overwhelms the variegated changing autumnal coat), they clothe the animal in a thick white outer garment, generally assumed about the first week of December. As soon as the new growth renders itself superficially evident, the change of colour in the old hair, which on the back up to this time has been slow in progress, advances with great rapidity, so that in a few days only a few coloured hairs, generally remaining unchanged throughout the whole winter, are to be detected. The feet and ears, the first to show indications of change, are the last in completing the winter hue: generally the head and ears have no hybernal fresh growth; but occasionally it is to be met with. During this period, and especially when the new hybernal growth of white hair renders itself conspicuous on the surface of the autumnal coat, an extremely handsome fur is produced; every degree of variation may be met with, and each step of the process can be traced with accuracy and clearness. Modifications of the progressive changes enumerated above often occur in individuals, from an anticipation or retardation of change in one part relatively to the whole ; these, however, are of a temporary nature-mere individual peculiarities, and finally merge into the all but universal midwinter clothing, which may be described as under. A white, with a leaden tinge, from a few long black hairs undergoing no change, pervades the entire skin, with the exception of the edges of the ears, eyelids, and legs; a narrow rim of black hair, ^ inch wide, is present at the tip of the ear externally and 1^ inch downwards on each side of the cartilage, which is thrown into strong relief by the thick white woolly coat now existent on the inside ; a narrow rim, also black, on the free edge of the eyelids ; the whiskers white entirely, or interspersed with some not changed, the shaft of hair white only at tip, or with alternating white and black bands ; the anterior surface of the feet mottled reddish white,- the colour of the ears and eyelids being the resultant of no change in these situations, that of the feet and whiskers from a non-completion of the process. However, although this is the general rule, yet it is not difficult to find specimens where the length of the hybernal growth on the ears and around the eyes conceals the normal black, and the absolute completion of change elsewhere obliterates these peculiarities, leaving the animal snowy white, broken only by the glistening dark-brown pupil of the eye and yellowish iris. Contrasting the winter with the summer and autumnal coat we find a colour-change with a great increase in the length and thickness of the fur ; let us inquire minutely into the process and its local modifications. On the back is to be distinguished the pile and undergrowth. The former is made up of straight pointed hairs, slightly varying in length, the average l^inch, and white throughout the entire shaft, mingled with a few isolated black hairs and |
