and animals, John Hunter showed that the essential difference between
the so-called warm-blooded and cold-blooded animals lies in the
constancy of the temperature of the former, and the variability of
the temperature of the latter. Those animals high in the scale of
evolution, as birds and mammals, have a high temperature almost
constant and independent of that of the surrounding air, whereas
among the lower animals there is much variation of body temperature,
dependent entirely on their surroundings. There are, however, certain
mammals which are exceptions, being warm-blooded during the summer,
but cold-blooded during the winter when they hibernate; such are the
hedgehog, bat and dormouse. John Hunter suggested that two groups
should be known as "animals of permanent heat at all atmospheres" and
"animals of a heat variable with every atmosphere," but later
Bergmann suggested that they should be known as "homoiothermic" and
"poikilothermic" animals. But it must be remembered there is no hard
and fast line between the two groups. Also, from work recently done
by J.O. Wakelin Barratt, it has been shown that under certain
pathological conditions a warm-blooded (homoiothermic) animal
may become for a time cold-blooded (poikilothermic). He has shown
conclusively that this condition exists in rabbits suffering from
rabies during the last period of their life, the rectal temperature
being then within a few degrees of the room temperature and varying
with it. He explains this condition by the assumption that the nervous
mechanism of heat regulation has become paralysed. The respiration and
heart-rate being also retarded during this period, the resemblance
to the condition of hibernation is considerable. Again, Sutherland
Simpson has shown that during deep anaesthesia a warm-blooded animal
tends to take the same temperature as that of its environment. He
demonstrated that when a monkey is kept deeply anaesthetized with
ether and is placed in a cold chamber, its temperature gradually
falls, and that when it has reached a sufficiently low point (about
25° C. in the monkey), the employment of an anaesthetic is no longer
necessary, the animal then being insensible to pain and incapable of
being roused by any form of stimulus; it is, in fact, narcotized
by cold, and is in a state of what may be called "artificial
hibernation." Once again this is explained by the fact that the
heat-regulating mechanism has been interfered with. Similar results
have been obtained from experiments on cats. These facts--with
many others--tend to show that the power of maintaining a constant
temperature has been a gradual development, as Darwin's theory of
evolution suggests, and that anything that interferes with the due
working of the higher nerve-centres puts the animal back again, for
the time being, on to a lower plane of evolution.
[Illustration: Chart showing diurnal variation in body temperature,
ranging from about 37.5° C. from 10 A.M. to 6 P.M., and falling to
about 36.3° C. from 2 A.M to 6 A.M.]
_Variations in the Temperature of Man and some other Animals_.--As
stated above, the temperature of warm-blooded animals is maintained
with but slight variation. In health under normal conditions the
temperature of man varies between 36° C. and 38° C., or if the
thermometer be placed in the axilla, between 36.25° C. and 37.5° C.
In the mouth the reading would be from .25° C. to 1.5° C. higher than
this; and in the rectum some .9° C. higher still. The temperature of
infants and young children has a much greater range than this, and is
susceptible of wide divergencies from comparatively slight causes.
Of the lower warm-blooded animals, there are some that appear to be
cold-blooded at birth. Kittens, rabbits and puppies, if removed from
their surroundings shortly after birth, lose their body heat until
their temperature has fallen to within a few degrees of that of the
surrounding air. But such animals are at birth blind, helpless and in
some cases naked. Animals who are born when in a condition of greater
development can maintain their temperature fairly constant. In strong,
healthy infants a day or two old the temperature rises slightly, but
in that of weakly, ill-developed children it either remains stationary
or falls. The cause of the variable temperature in infants and
young immature animals is the imperfect development of the nervous
regulating mechanism.
The average temperature falls slightly from infancy to puberty and
again from puberty to middle age, but after that stage is passed the
temperature begins to rise again, and by about the eightieth year is
as high as in infancy. A diurnal variation has been observed dependent
on the periods of rest and activity, the maximum ranging from 10 A.M.
to 6 P.M., the minimum from 11 P.M. to 3 A.M. Sutherland Simpson and
J.J. Galbraith have recently done much work on this subject. In their
first experiments they showed that in a monkey there is a well-marked
and regular diurnal variation of the body temperature, and that by
reversing the daily routine this diurnal variation is also reversed.
The diurnal temperature curve follows the periods of rest and
activity, and is not dependent on the incidence of day and night; in
monkeys which are active during the night and resting during the day,
the body temperature is highest at night and lowest through the day.
They then made observations on the temperature of animals and birds of
nocturnal habit, where the periods of rest and activity are naturally
the reverse of the ordinary through habit and not from outside
interference. They found that in nocturnal birds the temperature
is highest during the natural period of activity (night) and lowest
during the period of rest (day), but that the mean temperature is
lower and the range less than in diurnal birds of the same size. That
the temperature curve of diurnal birds is essentially similar to that
of man and other homoiothermal animals, except that the maximum occurs
earlier in the afternoon and the minimum earlier in the morning. Also
that the curves obtained from rabbit, guinea-pig and dog were quite
similar to those from man. The mean temperature of the female was
higher than that of the male in all the species examined whose sex had
been determined.
Meals sometimes cause a slight elevation, sometimes a slight
depression--alcohol seems always to produce a fall. Exercise and
variations of external temperature within ordinary limits cause very
slight change, as there are many compensating influences at work,
which are discussed later. Even from very active exercise the
temperature does not rise more than one degree, and if carried to
exhaustion a fall is observed. In travelling from very cold to very
hot regions a variation of less than one degree occurs, and the
temperature of those living in the tropics is practically identical
with those dwelling in the Arctic regions.
[v.02 p.0050]
_Limits compatible with Life._--There are limits both of heat and cold
that a warm-blooded animal can bear, and other far wider limits that a
cold-blooded animal may endure and yet live. The effect of too extreme
a cold is to lessen metabolism, and hence to lessen the production of
heat. Both katabolic and anabolic changes share in the depression, and
though less energy is used up, still less energy is generated. This
diminished metabolism tells first on the central nervous system,
especially the brain and those parts concerned in consciousness.
Both heart-beat and respiration-number become diminished, drowsiness
supervenes, becoming steadily deeper until it passes into the sleep of
death. Occasionally, however, convulsions may set in towards the end,
and a death somewhat similar to that of asphyxia takes place. In some
recent experiments on cats performed by Sutherland Simpson and
Percy T. Herring, they found them unable to survive when the
rectal temperature was reduced below 16° C. At this low temperature
respiration became increasingly feeble, the heart-impulse usually
continued after respiration had ceased, the beats becoming very
irregular, apparently ceasing, then beginning again. Death appeared to
be mainly due to asphyxia, and the only certain sign that it had
taken place was the loss of knee jerks. On the other hand, too high a
temperature hurries on the metabolism of the various tissues at such
a rate that their capital is soon exhausted. Blood that is too warm
produces dyspnoea and soon exhausts the metabolic capital of the
respiratory centre. The rate of the heart is quickened, the beats then
become irregular and finally cease. The central nervous system is also
profoundly affected, consciousness may be lost, and the patient falls
into a comatose condition, or delirium and convulsions may set in. All
these changes can be watched in any patient suffering from an acute
fever. The lower limit of temperature that man can endure depends on
many things, but no one can survive a temperature of 45° C. (113° F.)
or above for very long. Mammalian muscle becomes rigid with heat rigor
at about 50° C., and obviously should this temperature be reached the
sudden rigidity of the whole body would render life impossible. H.M.
Vernon has recently done work on the death temperature and paralysis
temperature (temperature of heat rigor) of various animals. He found
that animals of the same class of the animal kingdom showed very
similar temperature values, those from the Amphibia examined being
38.5° C., Fishes 39°, Reptilia 45°, and various Molluscs 46°. Also
in the case of Pelagic animals he showed a relation between death
temperature and the quantity of solid constituents of the body,
_Cestus_ having lowest death temperature and least amount of solids in
its body. But in the higher animals his experiments tend to show
that there is greater variation in both the chemical and physical
characters of the protoplasm, and hence greater variation in the
extreme temperature compatible with life.
_Regulation of Temperature._--The heat of the body is generated by the
chemical changes--those of oxidation--undergone not by any particular
substance or in any one place, but by the tissues at large. Wherever
destructive metabolism (katabolism) is going on, heat is being set
free. When a muscle does work it also gives rise to heat, and if
this is estimated it can be shown that the muscles alone during their
contractions provide far more heat than the whole amount given out
by the body. Also it must be remembered that the heart--also a
muscle,--never resting, does in the 24 hours no inconsiderable amount
of work, and hence must give rise to no inconsiderable amount of heat.
From this it is clear that the larger proportion of total heat of
the body is supplied by the muscles. These are essentially the
"thermogenic tissues." Next to the muscles as heat generators come the
various secretory glands, especially the liver, which appears never to
rest in this respect. The brain also must be a source of heat, since
its temperature is higher than that of the arterial blood with which
it is supplied. Also a certain amount of heat is produced by the
changes which the food undergoes in the alimentary canal before it
really enters the body. But heat while continually being produced is
also continually being lost by the skin, lungs, urine and faeces.
And it is by the constant modification of these two factors, (1)
heat production and (2) heat loss, that the constant temperature of
a warm-blooded animal is maintained. Heat is lost to the body through
the faeces and urine, respiration, conduction and radiation from
the skin, and by evaporation of perspiration. The following are
approximately the relative amounts of heat lost through these
various channels (different authorities give somewhat different
figures):--faeces and urine about 3, respiration about 20, skin
(conduction, radiation and evaporation) about 77. Hence it is clear
the chief means of loss are the skin and the lungs. The more air that
passes in and out of the lungs in a given time, the greater the loss
of heat. And in such animals as the dog, who do not perspire easily by
the skin, respiration becomes far more important.
But for man the great heat regulator is undoubtedly the skin, which
regulates heat loss by its vasomotor mechanism, and also by the
nervous mechanism of perspiration. Dilatation of the cutaneous
vascular areas leads to a larger flow of blood through the skin, and
so tends to cool the body, and _vice versa_. Also the special nerves
of perspiration can increase or lessen heat loss by promoting or
diminishing the secretions of the skin. There are greater difficulties
in the exact determination in the amount of heat produced, but there
are certain well-known facts in connexion with it. A larger living
body naturally produces more heat than a smaller one of the same
nature, but the surface of the smaller, being greater in proportion
to its bulk than that of the larger, loses heat at a more rapid rate.
Hence to maintain the same constant bodily temperature, the smaller
animal must produce a relatively larger amount of heat. And in the
struggle for existence this has become so.
Food temporarily increases the production of heat, the rate of
production steadily rising after a meal until a maximum is reached
from about the 6th to the 9th hour. If sugar be included in the meal
the maximum is reached earlier; if mainly fat, later. Muscular work
very largely increases the production of heat, and hence the more
active the body the greater the production of heat.
But all the arrangements in the animal economy for the production and
loss of heat are themselves probably regulated by the central nervous
system, there being a thermogenic centre--situated above the spinal
cord, and according to some observers in the optic thalamus.
AUTHORITIES.--M.S. Pembrey, "Animal Heat," in Schafer's _Textbook
of Physiology_ (1898); C.R. Richet, "Chaleur," in _Dictionnaire de
physiologie_ (Paris, 1898); Hale White, Croonian Lectures, _Lancet_,
London, 1897; Pembrey and Nicol, _Journal of Physiology_, vol. xxiii.,
1898-1899; H.M. Vernon, "Heat Rigor," _Journal of Physiology_, xxiv.,
1899; H.M. Vernon, "Death Temperatures," _Journal of Physiology_,
xxv., 1899; F.C. Eve, "Temperature on Nerve Cells," _Journal of
Physiology_, xxvi., 1900; G. Weiss, _Comptes Rendus, Soc. de Biol._,
lii., 1900; Swale Vincent and Thomas Lewis, "Heat Rigor of Muscle,"
_Journal of Physiology_, 1901; Sutherland Simpson and Percy Herring,
"Cold and Reflex Action," Journal of Physiology, 1905; Sutherland
Simpson, _Proceedings of Physiological Soc._, July 19, 1902;
Sutherland Simpson and J.J. Galbraith, "Diurnal Variation of Body
Temperature," _Journal of Physiology_, 1905; _Transactions Royal
Society Edinburgh_, 1905; _Proc. Physiological Society_, p. xx., 1903;
A.E. Boycott and J.S. Haldane, _Effects of High Temperatures on Man._
ANIMAL WORSHIP, an ill-defined term, covering facts ranging from the
worship of the real divine animal, commonly conceived as a "god-body,"
at one end of the scale, to respect for the bones of a slain animal or
even the use of a respectful name for the living animal at the other
end. Added to this, in many works on the subject we find reliance
placed, especially for the African facts, on reports of travellers who
were merely visitors to the regions on which they wrote.
[v.02 p.0051]
_Classification_.--Animal cults may be classified in two ways:
(A) according to their outward form; (B) according to their inward
meaning, which may of course undergo transformations.
(A) There are two broad divisions: (1) all animals of a given species
are sacred, perhaps owing to the impossibility of distinguishing the
sacred few from the profane crowd; (2) one or a fixed number of a
species are sacred. It is probable that the first of these forms is
the primary one and the second in most cases a development from it due
to (i.) the influence of other individual cults, (ii.) anthropomorphic
tendencies, (iii.) the influence of chieftainship, hereditary and
otherwise, (iv.) annual sacrifice of the sacred animal and mystical
ideas connected therewith, (v.) syncretism, due either to unity of
function or to a philosophic unification, (vi.) the desire to do
honour to the species in the person of one of its members, and
possibly other less easily traceable causes.
(B) Treating cults according to their meaning, which is not
necessarily identical with the cause which first led to the
deification of the animal in question, we can classify them under ten
specific heads: (i.) pastoral cults; (ii.) hunting cults; (iii.) cults
of dangerous or noxious animals; (iv.) cults of animals regarded as
human souls or their embodiment; (v.) totemistic cults; (vi.) cults
of secret societies, and individual cults of tutelary animals;
(vii.) cults of tree and vegetation spirits; (viii.) cults of ominous
animals; (ix.) cults, probably derivative, of animals associated with
certain deities; (x.) cults of animals used in magic.
(i.) The pastoral type falls into two sub-types, in which the species
(_a_) is spared and (_b_) sometimes receives special honour at
intervals in the person of an individual. (See _Cattle, Buffalo_,
below.)
(ii.) In hunting cults the species is habitually killed, but (_a_)
occasionally honoured in the person of a single individual, or (_b_)
each slaughtered animal receives divine honours. (See _Bear_, below.)
(iii.) The cult of dangerous animals is due (_a_) to the fear that the
soul of the slain beast may take vengeance on the hunter, (_b_) to a
desire to placate the rest of the species. (See _Leopard_, below.)
(iv.) Animals are frequently regarded as the abode, temporary or
permanent, of the souls of the dead, sometimes as the actual souls
of the dead. Respect for them is due to two main reasons: (_a_) the
kinsmen of the dead desire to preserve the goodwill of their dead
relatives; (_b_) they wish at the same time to secure that their
kinsmen are not molested and caused to undergo unnecessary suffering.
(See _Serpent_, below.)
(v.) One of the most widely found modes of showing respect to animals
is known as totemism (see TOTEM AND TOTEMISM), but except in decadent
forms there is but little positive worship; in Central Australia,
however, the rites of the Wollunqua totem group are directed towards
placating this mythical animal, and cannot be termed anything but
religious ceremonies.
(vi.) In secret societies we find bodies of men grouped together with
a single tutelary animal; the individual, in the same way, acquires
the nagual or individual totem, sometimes by ceremonies of the nature
of the bloodbond.
(vii.) Spirits of vegetation in ancient and modern Europe and in China
are conceived in animal form. (See _Goat_, below.)
(viii.) The ominous animal or bird may develop into a deity. (See
_Hawk_, below.)
(ix.) It is commonly assumed that the animals associated with certain
deities are sacred because the god was originally theriomorphic; this
is doubtless the case in certain instances; but Apollo Smintheus,
Dionysus Bassareus and other examples seem to show that the god may
have been appealed to for help and thus become associated with the
animals from whom he protected the crops, &c.
(x.) The use of animals in magic may sometimes give rise to a kind
of respect for them, but this is of a negative nature. See, however,
articles by Preuss in _Globus_, vol. lxvii., in which he maintains
that animals of magical influence are elevated into divinities.
_Animal Cults._
_Bear_.--The bear enjoys a large measure of respect from all savage
races that come in contact with it, which shows itself in apologies
and in festivals in its honour. The most important developments of
the cult are in East Asia among the Siberian tribes; among the Ainu of
Sakhalin a young bear is caught at the end of winter and fed for
some nine months; then after receiving honours it is killed, and the
people, who previously show marks of grief at its approaching fate,
dance merrily and feast on its body. Among the Gilyaks a similar
festival is found, but here it takes the form of a celebration in
honour of a recently dead kinsman, to whom the spirit of the bear
is sent. Whether this feature or a cult of the hunting type was the
primary form, is so far an open question. There is a good deal of
evidence to connect the Greek goddess Artemis with a cult of the bear;
girls danced as "bears" in her honour, and might not marry before
undergoing this ceremony. The bear is traditionally associated with
Bern in Switzerland, and in 1832 a statue of Artio, a bear goddess,
was dug up there.
_Buffalo_.--The Todas of S. India abstain from the flesh of their
domestic animal, the buffalo; but once a year they sacrifice a bull
calf, which is eaten in the forest by the adult males.
_Cattle_.--Cattle are respected by many pastoral peoples; they live
on milk or game, and the killing of an ox is a sacrificial function.
Conspicuous among Egyptian animal cults was that of the bull, Apis. It
was distinguished by certain marks, and when the old Apis died a new
one was sought; the finder was rewarded, and the bull underwent four
months' education at Nilopolis. Its birthday was celebrated once a
year; oxen, which had to be pure white, were sacrificed to it; women
were forbidden to approach it when once its education was finished.
Oracles were obtained from it in various ways. After death it was
mummified and buried in a rock-tomb. Less widespread was the cult of
the Mnevis, also consecrated to Osiris. Similar observances are found
in our own day on the Upper Nile; the Nuba and Nuer worship the bull;
the Angoni of Central Africa and the Sakalava of Madagascar keep
sacred bulls. In India respect for the cow is widespread, but is of
post-Vedic origin; there is little actual worship, but the products of
the cow are important in magic.
_Crow_.--The crow is the chief deity of the Thlinkit Indians of N.W.
America; and all over that region it is the chief figure in a group of
myths, fulfilling the office of a culture hero who brings the light,
gives fire to mankind, &c. Together with the eagle-hawk the crow plays
a great part in the mythology of S.E. Australia.
_Dog_.--Actual dog-worship is uncommon; the Nosarii of western Asia
are said to worship a dog; the Kalangs of Java had a cult of the red
dog, each family keeping one in the house; according to one authority
the dogs are images of wood which are worshipped after the death of a
member of the family and burnt after a thousand days. In Nepal it
is said that dogs are worshipped at the festival called Khicha Puja.
Among the Harranians dogs were sacred, but this was rather as brothers
of the mystae.
_Elephant_.--In Siam it is believed that a white elephant may contain
the soul of a dead person, perhaps a Buddha; when one is taken the
capturer is rewarded and the animal brought to the king to be kept
ever afterwards; it cannot be bought or sold. It is baptized and fêted
and mourned for like a human being at its death. In some parts of
Indo-China the belief is that the soul of the elephant may injure
people after death; it is therefore fêted by a whole village. In
Cambodia it is held to bring luck to the kingdom. In Sumatra the
elephant is regarded as a tutelary spirit. The cult of the white
elephant is also found at Ennarea, southern Abyssinia.
_Fish_.--Dagon seems to have been a fish-god with human head and
hands; his worshippers wore fish-skins. In the temples of Apollo and
Aphrodite were sacred fish, which may point to a fish cult. Atargatis
is said to have had sacred fish at Askelon, and from Xenophon we read
that the fish of the Chalus were regarded as gods.
_Goat_.--Dionysus was believed to take the form of a goat, probably as
a divinity of vegetation. Pan, Silenus, the Satyrs and the Fauns were
either capriform or had some part of their bodies shaped like that of
a goat. In northern Europe the wood spirit, Ljesche, is believed to
have a goat's horns, ears and legs. In Africa the Bijagos are said to
have a goat as their principal divinity.
_Hare_.--In North America the Algonquin tribes had as their chief
deity a "mighty great hare" to whom they went at death. According to
one account he lived in the east, according to another in the north.
In his anthropomorphized form he was known as Menabosho or Michabo.
[v.02 p.0052]