together my observations on the less known animals. The Tucutuco is exceedingly
abundant in the neighbourhood of Maldonado, but it is difficult to be procured,
and still more difficult to be seen, when at liberty. Azara,* who has given
an account of its habits, with wliich every thing I saw perfectly agrees, states that
he never was able to catch more than one, although they are so extremely common,
The Tucutuco lives almost entirely under ground, and prefers a sandy soil
with a gentle inclination ; hut it sometimes frequents damp places, even on the
borders of lakes. The burrows are said not to be deep, but of great length.
They are seldom open ; the earth being thrown up at the mouth into hillocks not
quite so large as those made by the mole. Considerable tracts of country are
completely undermined by these animals. They appear, to a certain degree, to
be gregarious ; for the man who procured my specimens had caught six together,
and he said this was a common occurrence. They are nocturnal in their habits ;
and their principal food is afforded by the roots of plants, which is the object of
their extensive and superficial burrows. In the stomach of one which I opened I
could only distinguish, amidst a yellowish green soft mass, a few vegetable fibres.
Azara states that they lay up magazines of food within their burrows.
“ The Tucutuco is universally known by a very peculiar noise, wliich it makes
when beneath the ground. A person, the first time he hears it, is much surprised ;
for it is not easy to tell whence it comes, nor is it possible to guess wliat kind of
creature utters it. The noise consists in a short, but not rough, nasal grunt,
which is repeated about four times in quick succession ; the first grunt is not so
loud, but a little longer, and more distinct than the three following : the musical
time of the whole is constant, as often as it is uttered. The name Tucutuco is
given in imitation of the sound. In all times of the day, where this animal is
abundant, the noise may be heard, and sometimes directly beneath one’s feet.
When kept in a room, the Tucutucos move both slowly and clumsily, which
appears owing to the outward action of their hind legs ; and they are likewise
quite incapable of jumping even the smallest vertical height. Mr. Reid, who
dissected a specimen which I brought home in spirits, informs me that the
socket of the thigh-bone is not attached by a ligamentum teres ; and tliis explains,
in a satisfactory manner, the awkward movements of their hinder extremities.
Their teeth are of a bright wax yellow, and are never covered by the
lips : they are not adapted to gnaw holes or cut wood. When eating any thing,
for instance biscuit, they rested on their hind legs and held the piece in their fore
paws ; they appeared also to wish to drag it into some corner. They were very
stupid ill making any attempt to escape ; when angry or frightened, they uttered
* Azara’s Voyages dans l'Amérique Méridionale, vol. i. p. 324.
the Tucutuco. Of those I kept alive, several, even the first day, were quite tame,
not attempting to bite or to run away; others were a little wilder. The man who
caught them asserted that very many are invariably found blind. A specimen
which I preserved in spirits was in this state ; Mr. Reid considers it to be the
effect of inflammation in the nictitating membrane. When the animal was alive,
I placed my finger within half an inch of its head, but not the slightest notice was
taken of it : it made its way, however, about the room nearly as well as the
others. Considering the subterranean habits of the Tucutuco, the blindness,
though so frequent, cannot be a very serious evil; yet it appears strange that any
animal should possess an organ constantly subject to injury. The mole, whose
habits in nearly every respect, excepting in the kind of food, are so similar, has
ail extremely small and protected eye, whioh, although possessing a limited
vision, at once seems adapted to its manner of life.
" Several species probably will be found to exist south of the Plata. At Bahia
Blanca (Lat. 39°) an animal burrows under ground in the same manner as the
C. Braziliensis, and its noise is of the same general character, but instead of
being double and repeated twice at short intervals, it is single and is uttered
either at equal intervals, or in an accelerating order. I was assured by the inhabitants
that these animals are of various colours, and, therefore, I presume that
the two kinds of noises proceeded from two species. However this may be, they
are extraordinarily numerous : many square leagues of country between the Sierras
Ventana and Guetru-heigue are so completely undermined by their burrows,
that horses in passing over the plain, sink, almost every step, fetlock deep. At
the Rio Negro (Lat. 41°) some closely allied (or same?) species utters a noise,
which is repeated only twice, instead of three or four times as with the La Plata
kind. The sound is, moreover, louder and more sonorous; and so closely resembles
that made in cutting down a small tree with an axe, that I have occasionally
remained in doubt for some time to which cause to attribute it. Where
the plains of Patagonia are very gravelly (as at Port Desire and St. Julian) the
Ctenomys, I believe, does not o c c ti-; but at Cape Negro, in the Strait of Magellan,
where the soil is damper and more sandy, the whole plain is studded with the
little hillocks, thrown up by this destructive animal. It occurs likewise south of
the Strait, on the eastern side of Tierra del Fuego, where the land is level.
Captain King brought home a specimen from the northern side of the Strait,
which Mr. Bennett* has called C. ilagellanicus: it is of a different colour from
the C. Braziliensis. I unfortunately did not make any note regarding the noise
of this southern species: but the circumstance of its existence rather corroborates
my belief in there being several other kinds in the neighbourhood of the Rio
* Transactions of the Zoological Society, vol. ii. p. 84.