154
THE ESSEX NATURALIST
vertebral stripe is very faint and the spots are almost invisible.
The ventral surface is a mushroom grey. There are signs of
shedding in the coat.
64/64. Female killed 12th April 1964. As 178/63 but in-
creased signs of shedding.
91 /64. Male killed 3rd May 1964. The coat is thick and long,
ragged in appearance where it is coming away in patches. Shed-
ding is most marked over the withers, and the hair at the base of
the neck has a fluffy appearance. The colour is a dull dark brown
except around the caudal disc and tail which are black. Neither
dapple nor vertebral stripe are apparent. Where the winter coat
has come away, the glossy black hairs of the summer coat can be
seen. The ventral surface of the body is a silvery grey colour
with a trace of sandiness between the hind legs.
At this stage it would be unwise from the present specimens to
generalise about the loss and development of the seasonal coats.
At present it would appear that the summer coat in both sexes
is a glossy black colour with a well-marked vertebral stripe and
light coloured dappling. The caudal disc is black. The ventral
surface of the animal may be grey though there may be sandy
coloured patches.
The female number 445/63 shows no obvious signs of a winter
coat, but the male, 448/63, killed two days later on 23rd October
shows clear evidence of this. By the end of the month of October
both a male (452/63) and a female (453/63) have begun to grow
the winter coat. Thus in 1963 both males and females were
developing winter coats by the end of October.
The winter coat appears to result from the growth of new,
longer hairs, dark brown in colour, and a general increase in
density and length of the hairs of the summer coat. The latter
could be a misinterpretation of an apparent thickening of the
hairs judged in some specimens. When further work is under-
taken on this process, detailed counts and measurements will be
taken. This new growth begins over the withers, the base of
the neck, and spreads posteriorly along the vertebral stripe and
ventrally over the back. When completed it covers the back,
apart from the posterior portion of the vertebral stripe, the tail
and caudal disc which remains black, and obliterates the light
dappling of the summer coat. The colour of the ventral surface
also appears to change from a silvery-grey to a mushroom-grey,
though no succession of change seems apparent in the present
specimens. Maximum development of the winter coat had been
achieved by the end of February (46/64). No specimens are
available from the intervening period. The next two specimens
(178/63 and 64/64) both show this maximum development and
the beginning of the moult in early April. At the time of writing,
24th June 1964, the last specimen received in this sequence is the
male (91/64). This shows the hair of the winter coat coming