60 MALD ON AD O. 1832-3.
frightened, they uttered the tucu-tuco. Of those I kept
alive, several, even the first day, became 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, and not the slightest notice was taken : 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;
y’et it appears strange that any animal should possess an organ
constantly subject to injury. The mole, whose habits m
nearly every respect, excepting in the kind of food, are so
similar, has an extremely small and protected eye, which,
although possessing a limited vision, at once seems adapted
to its manner of life.
Birds of many kinds are extremely abundant on the undulating
grassy plains around Maldonado. Several species,
of the genus Cassicus, allied to our starlings in habits
and structure, and of Tyrant-flycatchers, and a mockingbird,
from their numbers, give a character to the ornithology.
Some of the Cassici are very beautiful, black and yellow
being the prevailing colours; but Oriolus ruber, Gme., offers
an exception, in having its head, shoulders, and thighs of the
most splendid scarlet. This bird differs from its congeners
in being solitary. It frequents marshes ; and, seated on the
summit of a bw bush, with its mouth wide open, utters a
plaintive agreeable cry, which can be heard at a long distance.
Another species,* of a purplish-black colour, with a metallic
lustre, feeds on the plain in large flocks, mingled
. L e T r o u p ia l e c om m u n o f A z a r a (v o l. iii., p . 1 6 9 ) - a s e co n d sp ecie s
o f M o lo th n is .
1832-3. O RNITH OLO GY. G1
with other birds. Several may often be seen standing on
the back of a cow or horse. While perched on a hedge, and
pluming themselves in the sun, they sometimes attempt to
sing, or rather to hiss : the noise is very peculiar; it resembles
that of bubbles of air passing rapidly from a small
orifice under water, so as to produce an acute sound. Azara
states that this bird, like the cuckoo, deposits its eggs in
other birds’ nests. I was several times told by the country
people, that there was some bird with this habit; and my
assistant in collecting, who is a very accurate person, found
a nest of the sparrow* of the country, with one egg in it
larger than the others, and of a different colour and shape.
Mr. Swainsont has remarked that with the exception of the
Molothrus pecoris, the cuckoos are the only birds which can
be called truly parasitical; namely, such as « fasten themselves,
as it were, on another living animal, whose animal
heat brings their young into life, whose food they alone live
upon, and whose death would cause theirs during the period
of infancy.” The Molothrus pecoris is a North-American
bird, and is closely allied in general habits, even in such
peculiarities as standing on the backs of cattle (as its name
implies), and in appearance, with the species from the plains
of La Plata ; it only differs in being rather smaller and of a
different colour, yet the two birds would be considered by
every naturalist as distinct species. It is very mterestin<v to
see so close an agreement in structure, and in habits, between
allied species coming from opposite parts of a great
continent. It is also very remarkable, that the cuckoos and
the molothri, although opposed to each other in almost
every habit, should agree in the one strange one of their
parasitical propagation. The molothrus, like our starling, is
* A Z o n o tric h ia ; - t h e chingoh o f A z a r a , T h e eg g is r a th e r less th a n
t h a t o f t h e m is s e l-th ru sh ; i t is o f a n e a rly g lo b u la r fo rm , b u t w ith o n e e n d
r a th e r sm a lle r th a n th e o th e r . T h e g ro u n d c o lo u r is a p a le p in k is h
w h ite w ith irr e g u la r s p o ts a n d b lo tc iie s o f a p in k is h b row n , a n d o th e r s
less d is tm c t o f a g ray ish h u e . T h e egg is n ow in th e m u se um o f th e
Z o o lo g ic a l So ciety .
t M ag a z in e o f Z o o lo g y a n d B o ta n y , v o l. i., p . 2 17.
fjj.