30 OBSERVATIONS ON THE ANATOMY OF 
carnosus in the Ornithorynchus paradoxus : under the 
skin of the tail it degenerates mostly into a cellular tissue, 
in which is deposited a dark-yellow fatty matter. We may 
readily imagine the great powers possessed by this, the most 
extensive muscle of the body, over the viscera contained 
within it; and how, being only a little increased in the 
Echidna, this latter should thereby be enabled to roll itself 
vip into the form of a ball, after the manner of the common 
hedge-hog. 
The skin and subcutaneous cellular tissue abounded so 
much with oil, as to render this part of the dissection un- 
pleasant ; the cellular tissue betwixt the panniculus carno- 
sus and subjacent muscles was coarse, and in many places 
assumed the form of semitendinous fasciae. The skin ex- 
tending beyond the toes of the anterior extremity contains 
within its substance five narrow longitudinal horny pro- 
cesses, resembling that which is found within the integu- 
ments of the upper mandible ; the two innermost toes of 
the hind feet are likewise characterized by a process of the 
skin extending beyond the nails. I shall consider the bill 
of the Ornithorynchus as the organ of touch, by means of 
which the animal searches for its food; the supply of 
nerves is such as to render it the most perfect instrument 
of the kind with which we are acquainted. The length 
of the upper mandible, including the flap, is three inches 
nearly ; that of the lower bill, and flap, only two. 
The organs of taste and smell will not detain us long : 
the latter organ, indeed, could not be properly examined, as I 
was not at liberty to injure the bones of the face ; it is pro- 
bably not very energetic. The nostrils open anteriorly near 
the point of the upper mandible ; the anatomy of the pos- 
terior nares is regular, as in the Mammalia. The tongue 
has already been sufficiently well described by authors ; it 
is covered with a thick cuticle, and cannot be considered 
