BATRACHIANS AND REPTILES.
ON the intelligence of frogs and toads very little has to be said. Frogs
seem to have definite ideas of locality; for several of my
correspondents inform me that they have known cases in which these
animals, after having been removed for a distance of 200 or 300 yards
from their habitual haunts, returned to them again and again. This,
however, may I think perhaps be due to these haunts having a moistness
which the animals are able to perceive at a great distance. But be this
as it may, certainly the distance at which frogs are able to perceive
moisture is surprising. Thus, for instance, Warden gives a case in which
a pond containing a number of frogs dried up, and the frogs thereupon
made straight for the nearest water, although this was at a distance of
eight kilometres.[130]
A curious special instinct is met with in the toad _Bufo obstetricans_,
from which it derives its name; for the male here performs the function
of an accoucheur to the female, by severing from her body the gelatinous
cord by which the ova are attached.
Another special instinct or habit manifested by toads is described by M.
Duchemin in a paper before the Academy of Sciences at Paris.[131] The
habit consists in the killing of carp by squatting on the head of the
fish and forcing the fore-feet into its eyes. Probably this habit arises
from sexual excitement on the part of the toads.
I have one case, communicated to me by a correspondent, of a frog which
learnt to know her voice, and to come when called. As fish will
sometimes do the same thing, the account is sufficiently credible for
me to quote:--
I used to open the gate in the railings round the
pond, and call out 'Tommy' (the name I had given it),
and the frog would jump out from the bushes, dive into
the water, and swim across to me--get on my hand
sometimes. When I called 'Tommy,' it would nearly
always come, whatever the time of day, though it was
only fed after breakfast; but it seemed quite tame.
A very similar case is recorded by Mr. Pennent[132] of a toad which was
domesticated for thirty-six years, and knew all his friends.
There is no doubt that frogs are able to appreciate coming changes of
weather, and to adapt their movements in anticipation of them; but these
facts show delicate sensibility rather than remarkable intelligence.
The following observation of Edward, the Scottish naturalist, however,
shows considerable powers of observation on the part of frogs. After
describing the great noise made by a number of frogs on a moonlight
night, he says:--
Presently, when the whole of the vocalists had reached
their highest notes, they became hushed in an instant.
I was amazed at this, and began to wonder at the
sudden termination of the concert. But, looking about,
I observed a brown owl drop down, with the silence of
death, on to the top of a low dyke close by the
orchestra.[133]
_Reptiles._
Like the other cold-blooded Vertebrata, the reptiles are characterised
by a sluggishness and low development of mental power which is to some
extent proverbial. Nevertheless, that some members of the class present
vivid emotions is not to be questioned. Thus, to quote from Thompson:--
The common guana (_Lacerta iguana_) is naturally
extremely gentle and harmless. Its appearance,
however, is much against it, especially when agitated
by fear or anger. Its eyes then seem on fire; it
hisses like a serpent, swells out the pouch under its
throat, lashes about its long tail, erects the scales
on its back, and extending its wide jaws, holds its
head, covered over with tubercles, in a menacing
attitude. The male, during the spring of the year,
exhibits great attachment towards the female. Throwing
aside his usual gentleness of character, he defends
her even with fury, attacking with undaunted courage
every animal that seems inclined to injure her; and at
this time, though his bite is by no means poisonous,
he fastens so firmly, that it is necessary either to
kill him or to beat him with great violence on the
nose, in order to make him quit his hold.[134]
Several species of snake incubate their eggs and show parental affection
for their young when they are hatched out; but neither in these nor in
any other of their emotions do the reptiles appear to rise much above
the level of fish. The case, however, which I shall afterwards quote, of
the tame snakes kept by Mr. and Mrs. Mann, seems to show a somewhat
higher degree of emotional development than could be pointed to as
occurring in any lower Vertebrata. Moreover, according to Pliny, so much
affection subsists between the male and female asp, that when the one is
killed the other seeks to avenge its death; and this statement is so far
confirmed--or rather, its origin explained--by Sir Emerson Tennent that
he says when a cobra is killed, its mate is often found on the same spot
a day or two afterwards.
Passing on to the general intelligence of reptiles, we shall find that
this also, although low as compared with the intelligence of birds and
mammals, is conspicuously higher than that of fish or batrachians.
Taking first the case of special instincts, Mr. W. F. Barrett, in a
letter to Mr. Darwin, bearing the date May 6, 1873, and contained among
the MSS. already alluded to, gives an account of cutting open with a
penknife the egg of an alligator just about to hatch. The young animal,
although blind, 'instantly laid hold of the finger, and attempted to
bite.' Similarly, Dr. Davy, in his 'Account of Ceylon,' gives an
interesting observation of his own on a young crocodile, which he cut
out of the egg, and which, as soon as it escaped, started off in a
direct line for a neighbouring stream. Dr. Davy placed his stick before
it to try to make the little animal deviate from its course; but it
stoutly resisted the opposition, and raised itself into a posture of
offence, just as an older animal would have done.
Humboldt made exactly the same observation with regard to young turtles,
and he remarks that as the young normally quit the egg at night, they
cannot see the water which they seek, and must therefore be guided to it
by discerning the direction in which the air is most humid. He adds that
experiments were made which consisted in putting the newly hatched
animals into bags, carrying them to some distance from the shore, and
liberating them with their tails turned towards the water. It was
invariably found that the young animals immediately faced round, and
took without hesitation the shortest way to the water.
Scarcely less remarkable than the instincts of the young turtles are
those of the old ones. Their watchful timidity at the time of laying
their eggs is thus described by Bates:--
Great precautions are obliged to be taken to avoid
disturbing the sensitive turtles, who, previous to
crawling ashore to lay, assemble in great shoals off
the sand-bank. The men during this time take care not
to show themselves, and warn off any fisherman who
wishes to pass near the place. Their fires are made in
a deep hollow near the borders of the forest, so that
the smoke may not be visible. The passage of a boat
through the shallow waters where the animals are
congregated, or the sight of a man or a fire on the
sand-bank, would prevent the turtles from leaving the
water that night to lay their eggs; and if the causes
of alarm were repeated once or twice they would
forsake the praia for some other quieter place. . . .
I rose from my hammock by daylight, shivering with
cold--a praia, on account of the great radiation of
heat in the night from the sand, being towards the
dawn the coldest place that can be found in this
climate. Cardozo and the men were already up watching
the turtles. The sentinels had erected for this
purpose a stage about fifty feet high, on a tall tree
near their station, the ascent to which was by a
roughly made ladder of woody lianas. They are enabled,
by observing the turtles from this watch-tower, to
ascertain the date of successive deposits of eggs,
and thus guide the commandante in fixing the time for
the general invitation to the Ega people. The turtles
lay their eggs by night, leaving the water, when
nothing disturbs them, in vast crowds, and crawling to
the central and highest part of the praia. These
places are, of course, the last to go under water
when, in unusually wet seasons, the river rises before
the eggs are hatched by the heat of the sand. One
could almost believe, from this, that the animals used
forethought in choosing a place; but it is simply one
of those many instances in animals where unconscious
habit has the same result as conscious prevision. The
hours between midnight and dawn are the busiest. The
turtles excavate with their broad webbed paws deep
holes in the fine sand: the first comer, in each case,
making a pit about three feet deep, laying its eggs
(about 120 in number) and covering them with sand; the
next making its deposit at the top of that of its
predecessor, and so on until every pit is full. The
whole body of turtles frequenting a praia does not
finish laying in less than fourteen or fifteen days,
even when there is no interruption. When all have
done, the area (called by the Brazilians _taboleiro_)
over which they have excavated is distinguishable from
the rest of the praia only by signs of the sand having
been a little disturbed.[135]
The same naturalist says of the alligator,
These little incidents show the timidity and cowardice
(? prudence and caution) of the alligator. He never
attacks man when his intended victim is on his guard;
but he is cunning enough to know when this may be done
with impunity. Of this we had proof a few days
afterwards, &c.[136]
Of the alligator, Jesse writes:[137]--
But a most singular instance of attachment between two
animals, whose natures and habits were most opposite,
was related to me by a person on whose veracity I can
place the greatest reliance. He had resided for nine
years in the American States, where he superintended
the execution of some extensive works for the American
Government. One of these works consisted in the
erection of a beacon in a swamp in one of the rivers,
where he caught a young alligator. This animal he made
so perfectly tame that it followed him about the house
like a dog, scrambling up the stairs after him, and
showing much affection and docility. Its great
favourite, however, was a cat, and the friendship was
mutual. When the cat was reposing herself before the
fire (this was at New York), the alligator would lay
himself down, place his head upon the cat, and in this
attitude go to sleep. If the cat was absent the
alligator was restless; but he always appeared happy
when the cat was near him. The only instance in which
he showed any ferocity was in attacking a fox, which
was tied up in the yard. Probably, however, the fox
resented some playful advances which the other had
made, and thus called forth the anger of the
alligator. In attacking the fox he did not make use of
his mouth, but beat him with so much severity with his
tail, that, had not the chain which confined the fox
broken, he would probably have killed him. The
alligator was fed on raw flesh, and sometimes with
milk, for which he showed a great fondness. In cold
weather he was shut up in a box, with wool in it; but,
having been forgotten one frosty night, he was found
dead in the morning. This is not, I believe, a
solitary instance of amphibia becoming tame, and
showing a fondness for those who have been kind to
them. Blumenbach mentions that crocodiles have been
tamed; and two instances have occurred under my own
observation of toads knowing their benefactors, and
coming to meet them with considerable alacrity.
With regard to the higher intelligence of reptiles, I may quote the
following instances.
Three or four different correspondents tell me of cases which they have
themselves observed, of snakes and tortoises unmistakably distinguishing
persons. In one of these cases the tortoise would come to the call of
the favoured person, and when it came would manifest its affection by
tapping the boot of this person with its mouth; 'but it would not answer
anyone else.' A separation of some weeks did not affect the memory of
this tortoise for his friend.[138]
The following interesting observation on the intelligence of snakes
shows, not only that these animals are well able to distinguish persons,
and that they remember their friends for a period of at least six weeks,
but also that they possess an intensity of amiable emotion scarcely to
be expected in this class. Clearly the snakes in question were not only
perfectly tame, but entertained a remarkable affection for those who
tended and petted them. The facts were communicated to me by Mr. Walter
Severn, the well-known artist, who was a friend of Mr. and Mrs. Mann,
the gentleman and his wife to whom the snakes belonged. Mr. and Mrs.
Mann having got into trouble with their neighbours on account of the
fear and dislike which their pets occasioned, legal proceedings were
instituted, and so the matter came before the public. Mr. Severn then
wrote a letter to the _Times_, in order to show that the animals were
harmless. From this letter the following is an extract:--
I happen to know the gentleman and lady against whom a
complaint has been made because of the snakes they
keep, and I should like to give a short account of my
first visit to them.
Mr. M., after we had talked for a little time, asked
if I had any fear of snakes; and after a timid 'No,
not very,' from me, he produced out of a cupboard a
large boa-constrictor, a python, and several small
snakes, which at once made themselves at home on the
writing-table among pens, ink, and books. I was at
first a good deal startled, especially when the two
large snakes coiled round and round my friend, and
began to notice me with their bright eyes and forked
tongues; but soon finding how tame they were, I ceased
to feel frightened. After a short time Mr. M.
expressed a wish to call Mrs. M., and left me with the
boa deposited on an arm-chair. I felt a little queer
when the animal began gradually to come near, but the
entrance of my host and hostess, followed by two
charming little children, put me at my ease again.
After the first interchange of civilities, she and the
children went at once to the boa, and, calling it by
the most endearing names, allowed it to twine itself
most gracefully round about them. I sat talking for a
long time, lost in wonder at the picture before me.
Two beautiful little girls with their charming mother
sat before me with a boa-constrictor (as thick round
as a small tree) twining playfully round the lady's
waist and neck, and forming a kind of turban round
her head, expecting to be petted and made much of
like a kitten. The children over and over again took
its head in their hands and kissed its mouth, pushing
aside its forked tongue in doing so. The animal seemed
much pleased, but kept turning its head continually
towards me with a curious gaze, until I allowed it to
nestle its head for a moment up my sleeve. Nothing
could be prettier than to see this splendid serpent
coiled all round Mrs. M. while she moved about the
room, and when she stood to pour out our coffee. He
seemed to adjust his weight so nicely, and every coil
with its beautiful marking was relieved by the black
velvet dress of the lady. It was long before I could
make up my mind to end the visit, and I returned soon
after with a friend (a distinguished M.P.[139]), to see
my snake-taming acquaintance again. . . .
These (the snakes) seemed very obedient, and remained
in their cupboard when told to do so.
About a year ago Mr. and Mrs. M. were away for six
weeks, and left the boa in charge of a keeper at the
Zoo. The poor reptile moped, slept, and refused to be
comforted, but when his master and mistress appeared
he sprang upon them with delight, coiling himself
round them, and showing every symptom of intense
delight.[140]
The end of this python was remarkable and pathetic. Mr. Severn tells me
that some years after he had published the above letter Mr. Mann was
seized with an apoplectic fit. His wife, being the only other person in
the house at the time, ran out to fetch a doctor. She was absent about
ten minutes, and on returning found that the serpent during her absence
had crawled upstairs from the room below into that where her husband was
lying, and was stretched beside him dead. Such being the fact, we are
left to speculate whether the double seizure of the man and the snake
was a mere coincidence, or whether the sight of its stricken master,
acting on the emotions of a possibly not healthy animal, precipitated
its death. Looking to the extreme suddenness of the latter, as well as
to the fact of the animal having pined so greatly for his friends while
it was confined at the Zoological Gardens, I think the probability
rather points to the death of the animal having been accelerated by
emotional shock. But of course the question is an open one.
So much for the power of reptiles to establish such definite and
complete associations as are required for the recognition of
persons--associations, however, to which, as we have seen, frogs, and
even insects may attain. As for other associations, a correspondent
writes to me:--
I believe tortoises are able to establish a definite
association between particular colours on a flat
surface and food. Only the day before reading your
article on animal intelligence I noticed the
endeavours of a small tortoise to eat the _yellow_
flowers of an inlaid writing-table, and I have often
remarked the same recognition with regard to red.
Lord Monboddo relates the following anecdote of a serpent:--
I am well informed of a tame serpent in the East
Indies, which belonged to the late Dr. Vigot, and was
kept by him in the suburbs of Madras. This serpent was
taken by the French, when they invested Madras in the
late war, and was carried to Pondicherry in a close
carriage. But from thence he found his way back again
to his old quarters, which it seems he liked better,
though Madras is distant from Pondicherry about one
hundred miles. This information, he adds, I have from
a lady who then was in India, and had seen the serpent
often before his journey and after his return.
Considering the enormous distances over which turtles are able to find
their way in the season of migration, this display of the homing faculty
to so great a degree in a serpent is not to be regarded as incredible.
Mr. E. L. Layard, in his 'Rambles in Ceylon' says of the cobra:[141]--
I once watched one which had thrust its head through a
narrow aperture and swallowed one (_i.e._ a toad).
With this encumbrance he could not withdraw himself.
Finding this, he reluctantly disgorged the precious
morsel, which began to move off. This was too much for
snake philosophy to bear, and the toad was again
seized; and again, after violent efforts to escape,
was the snake compelled to part with it. This time,
however, a lesson had been learnt, and the toad was
seized by one leg, withdrawn, and then swallowed in
triumph.
Mr. E. C. Buck, B.C.S., says in 'Nature' (vol. viii., p. 303):--
I have witnessed exactly a similar plan pursued by a
large number of Ganges crocodiles, which had been
lying or swimming about all day in front of my tent,
at the mouth of a small stream which led from some
large inland lakes to the Ganges. Towards dusk, at the
same moment every one of them left the bank on which
they were lying, or the deep water in which they were
swimming, and formed a line across the stream, which
was about twenty yards wide. They had to form a double
line, as there was not room for all in a single line.
They then swam slowly up the shallow stream, driving
the fish before them, and I saw two or three fish
caught before they disappeared.
An account of reptile psychology would be incomplete without some
reference to the alleged facts of snakes charming other animals by
'fascination,' and being themselves charmed by the arts of music, &c.
The testimony on both subjects is conflicting, and especially with
regard to the fascination of other animals by snakes. Thus:--
Mr. Pennant says that this snake (rattle-snake) will
frequently lie at the bottom of a tree on which a
squirrel is seated. He fixes his eyes on the animal,
and from that moment it cannot escape; it begins a
doleful outcry, which is so well known that a
passer-by, on hearing it, immediately knows that a
snake is present. The squirrel runs up the tree a
little way, comes down again, then goes up, and
afterwards comes still lower. The snake continues at
the bottom of the tree with its eyes fixed on the
squirrel, and his attention is so entirely taken up,
that a person accidentally approaching may make a
considerable noise without so much as the snake
turning about. The squirrel comes lower, and at last
leaps down to the snake, whose mouth is already
distended for its reception. Le Vaillant confirms this
fascinating terror by a scene he witnessed. He saw on
the branch of a tree a species of shrike, trembling as
if in convulsions, and at the distance of nearly four
feet, on another branch, a large snake that was lying
with outstretched neck and fiery eyes, gazing steadily
at the poor animal. The agony of the bird was so great
that it was deprived of the power of moving away; and
when one of the party killed the snake, it (_i.e._ the
bird) was found dead upon the spot--and that entirely
from fear; for, on examination, it appeared not to
have received the slightest wound. The same traveller
adds that a short time afterwards he observed a small
mouse in similar agonising convulsions, about two
yards from a snake, whose eyes were intently fixed
upon it; and on frightening away the reptile, and
taking up the mouse, it expired in his hand.[142]
Many other observations, more or less similar, might be quoted; but, on
the other hand, Sir Joseph Fayrer tells me that 'fascination is only
fright;' and this appears to be the opinion of all persons who have had
the opportunity of looking into the subject in a scientific manner. The
truth probably is that small animals are occasionally much alarmed by
the sight of a snake looking at them, and as a consequence of this more
easily fall a prey. In some cases, it is likely enough, strong terror so
unnerves the animal as to make it behave in the manner which the
witnesses describe; in making half-palsied efforts to escape, it may
actually fall or draw nearer to the object of its dread. Perhaps,
therefore, Dr. Barton, of Philadelphia, is a little too severe on
previous observers when he says that--
The report of this fascinating property has had its
rise in nothing more than the fears and cries of birds
and other animals in the protection of their nests. . . .
The result of not a little attention has taught me
that there is but one wonder in the business--the
wonder that the story should ever have been believed
by any man of understanding and observation.
But, be this as it may, it is certainly remarkable, as Sir J. Fayrer in
his letter to me observes, 'how little fear some animals show until the
moment that they are seized and struck.'
As for snake-charming, the facts seem to be that cobras and other
serpents are attracted by the sound of a pipe to creep out of their
hiding-places, when they are captured and tamed. It is certain that the
fangs are not always drawn, and also that from the first moment of
capture, before there has been time for any process of training, a real
snake-charmer is able to make the reptile 'dance.' Thus, for instance,
Sir E. Tennent publishes the following letter from Mr. Reyne. After
describing all his precautions to ensure that the snake-charmer had no
tamed snakes concealed about his person, Mr. Reyne proceeds to tell how
he made the man accompany him to the jungle, where, attracted by the
music of a pipe which the man played, a large cobra came from an
ant-hill which Mr. Reyne knew it to occupy:--
On seeing the man it tried to escape, but he caught it
by the tail and kept swinging it round until we
reached the bungalow. He then made it dance, but
before long it bit him above the knee. He immediately
bandaged the leg above the bite and applied a
snake-stone to the wound to extract the poison. He was
in great pain for a few minutes, but after that it
gradually went away, the stone falling off just before
he was relieved.[143]
Thus the only remarkable thing about the charming of a freshly caught
snake seems to be that the charmer is able to make the animal
'dance'--for the fact of the snake approaching the unfamiliar sound of
music is not in itself any more remarkable than a fish approaching the
unfamiliar sight of a lantern. It does not, however, appear that this
dancing is anything more than some series of gestures or movements which
may be merely the expressions, more or less natural, of uneasiness or
alarm. Anything else that charmed snakes may do is probably the result
of training; for there is no doubt that cobras admit of being tamed, and
even domesticated. Thus, for instance, Major Skinner, writing to Sir E.
Tennent, says:--
In one family near Negombo, cobras are kept as
protectors, in the place of dogs, by a wealthy man who
has always large sums of money in his house. But this
is not a solitary case of the kind. . . . The snakes
glide about the house, a terror to the thieves, but
never attempting to harm the inmates.[144]
Thus, on the whole, we may accept Dr. Davey's opinion--who had good
opportunities for observation--that the snake-charmers control the
cobras by working upon the well-known timidity and reluctance of these
animals to use their fangs till they become virtually tame.
FOOTNOTES:
[130] _Account of the United States_, vol. ii., p. 9.
[131] April 11, 1870.
[132] See Bingley, _Animal Biography_, vol. ii., p. 406.
[133] Smiles, _Life of Edwards_, p. 124.
[134] _Passions of Animals_, p. 229.
[135] _Naturalist on the Amazon_, pp. 285-6.
[136] _Ibid._ The astonishing facts relating to the migration of turtles
in the laying season will be treated under the general heading
'Migration' in my forthcoming work.
[137] _Gleanings_, vol. i., pp. 163-4.
[138] The tortoise which has gained such immortal celebrity by having
fallen under the observation of the author of the _Natural History of
Selborne_, likewise distinguished persons in this way. For 'whenever the
good old lady came in sight, who had waited on it for more than thirty
years, it always hobbled with awkward alacrity towards its benefactress,
whilst to strangers it was altogether inattentive.'
[139] This gentleman was Lord Arthur Russell.
[140] The _Times_, July 25, 1872.
[141] See _Annas. and Mag. of Nat. Hist._, 2nd series, vol. ix., p. 333.
[142] Thompson, _Passions of Animals_, p. 118; see also Bingley, _Animal
Biography_, vol. ii., pp. 447-8.
[143] _Natural History of Ceylon_, p. 314.
[144] Tennent, _loc. cit._, p. 299.