252 
DRS. A. CARTE AND A. MACALISTER ON THE 
filaments of the sympathetic nerve formed a plexus in front of the renal artery and vein 
on each side. 
The spleen was single, extremely small, oval in shape, of a brownish-blue colour 
and attached to the left, or bulging of the first stomach, by a very short gastrosplenic 
omentum. 
Ear. 
The external auditory meatus opened on the surface by a very minute oval slit, whose 
longest diameter was about one line ; it was concealed at the bottom of a furrow in the 
integuments, which was situated about 7^ inches posterior to the external canthus of 
the eyelid, and on a line continued backwards horizontally from the commissure of the 
lips. From this aperture the auditory canal was continued backwards and inwards, 
winding round the posterior border of the squamous bone to reach the membrana tym- 
pani, where it terminated. The tube was readily separable from the deep-seated layers 
of the integuments, and was accompanied for a part of its extent by a fibrocartilaginous 
cord, which latter ceased about 3 inches from the superficial or tegumentary end of the 
meatus ; internally it was united to the posterior and external angle of the periotic bone. 
Immediately within the auditory meatus the calibre of the acoustic tube became 
slightly enlarged, but soon again resumed its original diameter ; its whole extent was 
filled with a dark, greyish, sebaceous substance, the product of a very distinct series of 
ceruminous glands, the orifices of whose ducts were visible on its lining membrane. The 
ear-tube itself was composed of three coats. First, an external or fibrocellular one, 
which, about 1^ inch from the external orifice, exhibited a thin stratum of circular 
muscular constrictor fibres enclosed in its layers ; second, a middle or fibrous coat, which 
was much the thickest and strongest; and third, an internal or pseudomucous lining 
membrane, which was formed by an involution of modified cuticle, and arranged in 
three longitudinal i. folds that commenced about three-quarters of an inch from the 
external meatus, and terminated at the dilated portion of the canal. 
The petrous or periotic bone was irregular in shape, and was lodged in a deep cavity 
between the squamous, pterygoid, basioccipital, and exoccipital bones ; it was separated 
from the last-named by the foramen lacerum posterius, which gave exit to jthe jugular 
vein. In this cavity it was loosely placed, being merely, fitted in, but not united by 
suture to the surrounding cranial bones, and consequently could be removed from the 
base of the skull without much difficulty. It presented four parts for description. First, 
a posterior or opisthotic; second, an anterior or prootic; third, a central or labyrinthic; 
and fourth, an inferior or tympanic. The opisthotic portion was prolonged backwards 
and outwards, being somewhat curved, with the concavity directed forwards ; it lay in a 
deep groove in the squamous bone external and anterior to the sulcus for the depressor 
maxillee inferioris, and was elongated, laterally compressed, and marked with irregular 
longitudinal ridges and furrows; where its lower edge was joined to the labyrinthic por- 
tion, it presented a prominent bony pedicle for the attachment of the tympanic element. 
