LIX. Anatomical Observations on the Structure of the Orni-
thorynchus Paradoxus. By J.F. Blumenbach, Pro-
fessor of Medicine at Göttingen, and Member of the Me-
dical Society of Paris^*.

THE specimen of this animal in my possession is about
19 inches in length; the head is 4 inches; the tail nearly
the same; and the neck and trunk 10 inches^†.

It is covered with two kinds of hair. The interior gray,
short, and very soft, like down; that on the outside, mixed
with others longer and stiffer, brownish on the back, and yel-
lowish on the belly.

The limbs are short. The sore feet are about 2½ inches
in length; the hind feet are somewhat longer. The feet
have sive toes, palmated’ (natatorii). The natatory mem-
branes of the sore feet are very broad, not inserted between
the toes, but attached below them, so as to be better calcu-
lated for diving.

The tail flat, and covered with stiff hair like bristles.

But what appears most singular and anomalous is the con-
formation of the head, being furnished with a broad beak
resembling that of a duck. The mandibles, spatula-formed,
are flat. The upper one, about 2 inches in length, and
1⅓ d in breadth.

These mandibles are covered with a coriaceous membrane,
which extends to the corners of their aperture.

The under mandible, which is narrow than the upper,
is serrated (a, fig. 1. Plate IX.) on the edges, as is the case in
a duck’s bill. The palate is furrowed across.

My specimen is destitute of teeth, like that described by
Dr. Shaw; but I have lately been informed, in a letter from
Sir Joseph Banks, that in another specimen two small dentes
molares have been found on each side of each mandible.

The whole beak at the root is edged with an undulated
membranaceous border running across it (b).

The conformation of the cranium, taken from the occi-
pital condyli (cd), and the intermaxillary bones (ef), has,
on the first view, a great resemblance to that of the duck.
The bones of the skull are divided by no futures; but the in-
terior chamber of the brain is divided by an osseous hook (g)
running lengthwise, which is found in no other quadruped^*,
and similar to that of the tetrao urogallus.

What seems to be highly worthy of notice, however, is
the remarkable apparatus of the nerves of the second branch
of the fifth pair, and the distribution of it in three regions of
the coriaceous membrane which surrounds the beak. The
nerve (h) which proceeds from the lower orbital foramen
goes to the transverse edge: the other (i), which issues be-
hind the intermaxillary bones, is distributed on the labial
edges: the third (k), which issues from the synchondrosis,
that divides the anterior hooked legs of the intermaxillary
bones, proceeds to the integument of the beak.

Comparing this large apparatus of maxillary nerves, with
which nature has provided this coriaceous integument, and
the like structure of the duck’s bill, there can scarcely be a
doubt that this highly sensible membrane, which surrounds
the beak, serves, in a very particular manner, in the ornitho-
rynchus, as in aquatic birds, for the purposes of feeling, by
means of which these animals can search for their food in
muddy places, where neither sight nor smell can be of any
use to them in that respect. Hence the eyes of the ornitho-
rynchus are very small, but the nostrils (lm) exceedingly
broad.

This wonderful animal, therefore, affords an exception to
the order of the internal senses assigned to quadrupeds by
Buffon^†, who says: ‘“In quadrupeds, smell is the first of
senses; taste is the second; or rather, these two form only
one: fight is the third; hearing the fourth; and feeling the
last.”’

In the annexed figure, one of the bones of the skull is re-
presented broken, that the interior of the chamber of the
brain may be seen. N, denotes the orbita; O, the zygoma;
PQ, the processus molares of each mandible. The other
parts will be understood from the preceding description.