Of the loir, or great dormouse, or as some naturalists have termed
it, the fat squirrel, there are three species; and, like the marmot,
they all sleep during the winter; namely, the loir, the lerot, and the
muscardin, or common dormouse. These three species have been confounded
together although they are very different, and easily distinguished.
The loir is nearly of the size of the squirrel, and like that animal,
has its tail covered with long hair; the lerot is not so large as a
rat, has very short hair on its tail, except at the extremity, where
there is a tuft of long hair; the dormouse is not bigger than the
common mouse, its tail is covered with longer hair than the lerot's,
but shorter than the loir's, and it also has a tuft at the extremity.
The loir differs from the other two, by having black spots about its
eyes, and the dormouse by having white hair upon his back. They are all
white or whitish under the neck and belly; the white of the lerot is
beautiful, that of the loir more dark, and that of the dormouse has a
yellow line in all the inferior parts.
_Engraved for Barr's Buffon._
[Illustration: FIG. 87. _Scrotine Bat._]
[Illustration: FIG. 88. _Horse-shoe Bat._]
[Illustration: FIG. 89. _Barbastelle Bat._]
[Illustration: FIG. 90. _Dormouse._]
[Illustration: FIG. 91. _Alpine Marmot._]
There is no truth in the assertion that these animals sleep during
winter, for they are not in a state of natural sleep, but in a torpor
produced by the coldness of the blood, by which they lose the use of
their senses and members. Their internal heat does not exceed the
temperature of the air. When the heat of the air is ten degrees above
the freezing point, their heat is exactly the same. The ball of a small
thermometer I have plunged into the bodies of several living lerots,
and always found the heat of their bodies was nearly equal to the
temperature of the air; and sometimes when applied to the very heart,
I have observed the thermometer fall from half a degree to a whole
one, the temperature of the air being at eleven. Now it is well known
that the internal heat of man, and of the generality of quadrupeds, at
all times exceeds thirty, and therefore there is little reason to be
surprised that these animals, whose heat is so small, should become
torpid, when their little internal heat ceases to be assisted by the
external heat of the air; a circumstance that naturally happens when
the thermometer is not above ten or eleven degrees above the freezing
point. This is the real cause of the torpor of these animals, a cause
which has been overlooked, although it extends to all animals which
sleep during winter. Alike are its effects upon these animals, the
hedge-hog and bats; and though I have never had the opportunity of
trying them upon the marmot, I am persuaded its blood is not less cold,
since like them it is subject to a torpor during winter.
The torpor continues as long as the cause which produces it, and ceases
with the cold. A few degrees of heat above ten or eleven is sufficient
to reanimate them, and if kept in a warm place during winter they
do not become torpid, but go about and eat and sleep, from time to
time, like other animals. When they feel the cold they crowd close
together, and roll themselves up like balls, in order to present a
smaller surface to the air, and to preserve some warmth. It is thus
they are found during winter in hollow trees, and in holes of walls
exposed to the south: in these they lie without motion, on moss and
leaves, and when taken, if tossed or rolled about they never stir, or
shew any signs of life; it is by a mild and gradual heat alone they
are to be recovered, for if carried suddenly near a fire they perish.
Though in this state they are without motion, though their eyes are
shut, and they seem to be deprived of all their senses, yet they feel
pain when it is very acute; they testify it when burned or wounded by
a contraction, and a little hollow cry, which they will repeat several
times; hence it is plain the internal sensibility must subsist, as
well as the action of the heart and lungs, yet it is to be presumed
that these vital motions act not with the same force and power while
in the torpid as in the usual state. The circulation, probably, is
not performed then but in the larger vessels; the respiration is slow
and feeble, the secretions are very scanty, and perspiration must be
nearly annihilated, since they could not pass several months without
eating were they to lose as much of their substance in proportion by
perspiration as they do when they have an opportunity of repairing it
by taking of sustenance; they do lose some part, however, since in
very long winters they die in their holes. Perhaps indeed it is not
the duration but the severity of the cold that cuts them off, as they
soon die if exposed to an intense frost. What induces me to believe
that it is not from waste of substance they perish in long winters, is
their being very fat in autumn, and equally so on their reviving in
spring; this abundance of fat being an internal substance, sufficient
to supply what they lose by perspiration. Besides, as cold is the sole
cause of their torpor, and they never fall into that state but when the
temperature of the air is beyond the tenth or eleventh degree, they
often revive during the winter, for in that season there are frequently
hours, and even days, in which the liquor will be found at the twelfth,
thirteenth, or fourteenth degree, and during this mild weather the
dormice quit their holes in search of food, or rather eat what they had
amassed the preceding autumn.
Aristotle asserted, and he has been followed by succeeding naturalists,
that dormice pass the whole winter without eating, and that during
this period of abstinence they become very fat, being more nourished
by sleep alone than other animals by food. This is both untrue and
impossible. In its torpid state, which lasts four or five months,
it could only fatten by the air it breathes; and allowing (which
however is granting too much) that part of this air is converted into
nourishment, could so considerable an increase result from it? Would
it be sufficient to recompense the waste by perspiration? Aristotle
might have been led into this error by the winters in Greece being
very mild, where the dormice do not sleep continually, but taking
nourishment every time they were revived by the warmth they might
become fat, though in a torpid state. The truth is they are always fat,
especially in autumn and summer. Their flesh is not unlike that of the
guinea-pig. They were reckoned delicacies by the Romans, who reared
great numbers of them. Varro describes the method of making warrens
for them, as does Apicius of dressing them in the best manner. Their
instructions, however, have been neglected, either from a disgust to
a loir from his near resemblance to a rat, or from his flesh being
unpalatable. I have been told by peasants who had eaten them, that it
is hardly preferable to that of the water-rat.
The loir has a considerable resemblance to the squirrel in its natural
habits; it lives in forests, climbs up trees, and leaps from branch to
branch, though not so nimbly as the latter, because his legs are not so
long, and he is as remarkable for being fat as the other is for being
slender. Nuts, and other wild fruits, compose the usual nourishment
of both; the loir likewise eats small birds, which he takes in their
nests. He does not, like the squirrel, nestle on the upper parts of
trees, but makes a bed of moss in the trunks of those which are
hollow; he also shelters himself in the clefts of rocks, and always
prefers dry places. He avoids moisture, drinks little, and rarely
descends to the ground; but there is a material difference between him
and the squirrel, as the latter is easily tamed, but the loir always
remains wild. They couple about the end of spring, and the females
bring forth in summer, generally producing four or five at a time.
Their growth is quick, and it is asserted that they do not live more
than six years. In Italy, where they still eat them, the inhabitants
dig pits in the woods, which they line and cover with straw and moss;
for these pits they chuse a dry spot, sheltered by rocks and exposed to
the south; to which the loirs resort in great numbers, and the people
find them there in a torpid state, about the end of autumn, when they
are fittest to eat. They are full of courage, and will defend their
lives to the last extremity; their fore-teeth are both long and strong,
and they bite violently; they have no fear of the weasel nor small
birds of prey; they baffle the attempts of the fox by mounting to the
tops of the trees, nor have they any very formidable enemies but the
martens and wild cats.
This species is not very much diffused; it is not met with in the cold
climates, such as Lapland and Sweden; at least the naturalists of the
north do not mention it; the species they describe being the muscardin,
the smallest of the three; neither, I presume are they to be met within
very hot climates, travellers being silent about them. There are few or
none of them in open countries like England; they require a temperate
climate, and the country covered with wood. We meet with them in Spain,
France, Greece, Italy, Germany, and Switzerland, where they live in
forests, upon hills, and not on the tops of mountains, like the marmot,
which, though subject to a torpor from the cold, seems to delight in
frost and snow.