The Hapalid^. MAMMALIA. The Marmozets. 41 
their period of activity is to a certain e.xtent nocturnal; 
but in the douroucouli, this character is carried to a 
far greater extent, and this animal and its allies are 
known to sleep through the day, and to roam about 
at night in search of their food. Their eyes, like those 
of the cats, are luminous in the dark ; their voice 
is very strong, and, according to Humboldt, resembles 
that of the jaguar. It seems probable, indeed, from a 
statement made by that author in his “ Aspects of 
Nature,” that the concert of fearful noises heard during 
the night in the forests of tropical America, and usually 
attributed to the howling monkeys alone, is due to the 
combined efforts of many different vocalists. 
The douroucouli shelters itself in the holes of large 
trees, and according to Humboldt, lives in pairs, and 
not in troops, like most other monkeys. Spix, how- 
ever, says that he has seen them going about in bands. 
The tail is long, but not prehensile, and the animal 
winds it round its body when in repose. The ears are 
almost entirely concealed by the long hairs on the sides 
of the head; the colour of the fur on the upper parts 
of the body is grey; the lower parts are orange, and 
this colour also appears on the sidiis of the neck. The 
forehead exhibits three black lines, diverging back- 
wards ; and the tail is yellowish-gre}', with the tip 
black. The length of the head and body is about ten 
inches, and that of the tail eleven. The douroucouli 
feeds princij)ally on insects, and also on small birds, 
which it easily surprises when they are asleep. 
Family HI.— HAPALID^. 
The Marmozets {HcipalidcB), forming the third 
family of the Quadrumana, and the second of the 
American monkeys, are distinguished from the Cebidse, 
to which they are in other respects very closelj'’ allied 
by the absence of the additional molar tooth, which, in 
the latter, occurs on each side in each jaw. Thus the 
total number of their teeth and that of the different 
kinds of teeth becomes the same as in man and the 
iiigher Quadrumana of the Old World. The tubercles 
of the molars are also more acute than in the Cebidse, 
indicating that the marmozets are more addicted to an 
animal diet, and, in fact, a great part of the nourish- 
ment of these creatures consists of insects, eggs of birds, 
and even small birds themselves, when these come 
within reach of the carnivorous little monkeys. Their 
tails are long and well-furred, but never prehensile. 
The marmozets are all of small size, rarely exceeding 
that of a squirrel ; their heads are small and rounded ; 
their ears usually provided with tufts of hair; the 
thumbs of the anterior hands are scarcely opposable, 
but those of the hinder pair are completely so, and 
these are furnished with flat nails whilst all the rest of 
the fingers bear claws. In every particular of their 
organization these monkeys show themselves to be 
inferior to the rest of the great group of Simise, and to 
approach more closelj' to the ordinary mammals, whilst 
the almost complete absence of convolutions on the 
surface of the brain would seem to indicate a degree 
of intelligence far below that, not only of the other 
Quadrumana, but even of the majority of the placental 
Mammalia. In this respect, indeed, the marmozets 
VoL. T. 6 
appear to approach the squirrels, with which they also 
have some other analogies ; they are incapable of the 
education which most of the other Simise and some of 
the Cebidse in particular, may be brought to receive, 
and their instinctive faculties are very highly developed. 
The extent of their intelligence will be seen from the 
particulars recorded by Audouin of the behaviour of 
two marmozets observed by him. In a picture they 
could recognize their own likeness, and those of flies, 
locusts, and beetles, the latter of which they endea- 
voured to seize with great avidity. The picture of a 
cat, on the other hand, and that of a wasp, caused them 
to shrink with terror, and when occupied in catching 
the flies which entered their cage, which they did with 
incredible dexterity, the appearance of a wasp attracted 
by a piece of sugar fixed in the bars, drove them at 
once to take refuge at the bottom of their cage. 
Astonished at this instinctive dread of an insect which 
they could never have seen before, Audouin took a 
wasp and brought it near the two marmozets, when 
they immediately hid their heads between their fore- 
hands and closed their eyes. But as soon as he substi- 
tuted for the wasp, a grasshopper, a beetle, or some 
other harmless insect, they darted upon it greedily and 
devoured it with the greatest gusto. Sugar and sweet 
fruits also constituted favourite articles of food with 
them, and the}' possessed the art of sucking eggs in 
great perfection. They would not eat flesh ; but when a 
small living bird was given to them, they would seize 
upon and kill it, then open its skull and devour the 
brain, at the same time licking up any blood that might 
flow ; they would also sometimes eat the bill, the 
tendons of the feet, and some other parts, but always 
avoided the flesh. Mr. A. R. Wallace during his 
voyage up the Amazon had an opportunity of observing 
many similar habits in specimens of several species of 
this family, which he kept in confinement. 
M. Audouin states that his marmozets recognized 
those who had the care of them, but this is opposed to 
the observations of most other naturalists, and must 
have been due to peculiar conditions in the individuals 
observed by the great French entomologist. 
In their native regions, the luxuriant forests of 
South America, these elegant little monkeys live 
amongst the trees in small troops, displaying, amongst 
the branches, an agility almost as great as that of the 
beautiful little inhabitant of our own woods — the 
squirrel. Their activity, however, is nocturnal. They 
produce as many as three young ones at a birth, which 
is an additional indication of their approach to the 
lower Mammalia; for the rest of the Quadrumana, and 
even the Cheiroptera, usually produce only a single 
young one ; and, as if to show this more clearly, it 
sometimes happens that when they breed in captivity, 
the mother will destroy one or more of her offspring, a 
circumstance which occurs still more frequently with 
the true Carnivora, and some of the Rodentia. Their 
young are born with their eyes open. 
From the foregoing account of the intellectual quali- 
fications of the marmozets it is evident, that the high 
esteem in which they were formerly held as pets must 
have been' due almost exclusively to the elegance of 
their form, and the agility of their movements; but 
