ANATOMY OF BALiEN OPTEEA EOSTEATA. 
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and was lost among the deep structures at the base of the skull ; and fourthly, the 
internal carotid, which formed part of the before-mentioned plexus, continuing its course 
into the cranial cavity to supply the brain through the medium of its rete mirabile, 
where its inosculating branches interlaced with those of the venous plexus at the base 
of the skull. 
The Masseter was a quadrilateral muscle consisting, as usual, of two planes of fibres, 
superficial and deep. The former arose by a flat tendon from the central portion of the 
inferior border of the orbit, from whence it ran downwards and backwards to be inserted 
into the posterior part of the angle of the lower jaw in front of the depressor maxillse 
inferioris ; a few of its fibres were inserted into the interarticular fibrocartilage. The 
latter or deeper set of fibres arose tendinous from the margin of the glenoid cavity, 
extending as far forwards as the posterior edge of the orbit ; the fibres of this plane ran 
downwards and a little forwards, and were inserted into the base of the lower jaw about 
3 inches in front of its angle, and occupied by its insertion about 3 inches of the outer 
surface of this bone. 
In a triangular space, bounded by the masto-humeral externally, the sternomastoid 
internally, and the pectoralis major below, corresponding to the posterior inferior triangle 
of the neck in the human subject, lay a considerable number of lymphatic glands, and 
also a very remarkable oval glanduloid body which, under the microscope, was found to 
consist of numerous cells or cavities imbedded in a matrix of loose fibro-areolar tissue, 
and into which very few blood-vessels were traceable ; these are probably the represen- 
tatives of the glandulse concatenate. 
On removing the integument and fascia from the abdominal wall, the following muscles 
were disclosed. 
External oblique. — This muscle arose by fleshy slips from the eight inferior ribs, and 
its origin was connected to the before-described muscular mass situated on the anterior 
part of the thorax ; its fibres ran downwards and inwards, forming a large tendinous 
expansion which covered the anterior part of the abdomen, and was inserted into the 
linea alba as far backwards as the anterior commissure of the cloacal sulcus ; a thin 
fascia was interposed between this and the following muscle. 
Internal oblique, which was situated beneath the foregoing, arose tendinous from 
the lumbar fascia as far backwards as the vulva ; its fibres ran forwards and inwards, 
and were inserted into the sternal cartilaginous extremities of the eight or nine inferior 
ribs, and into the linea alba as far forwards as the lower border of the sternum, and 
backwards to the anterior commissure of the vulval fissure. 
Transversalis abdominis. — This muscle lay deeper than the last described, and arose 
fleshy from the lumbar fascia, extending as far back as the posterior limit of the origin 
of the internal oblique, and continuing as far forwards as the tenth rib ; the fibres ran 
inwards, and were inserted tendinous into the linea alba, the entire insertion being 
situated on the deep-seated surface of the rectus abdominis. 
Rectus abdominis arose by a central tendon from the three or four anterior chevron 
