ing off e, the artery of
the thumb.

F. Pisiform bone.

G. Ulnar artery, giving off the branch I to join the deep palmar arch E
of the radial artery.

H. Ulnar nerve; h, superficial branches given to the fingers. Its deep
palmar branch is seen lying on the interosseous muscles, M M.

K. Abductor minimi digiti.

L. Flexor brevis minimi digiti.

M. Palmar interosseal muscles.

N. Tendons of flexor digitorum sublimis and profundus, and the
lumbricales muscles cut and turned down.

O. Tendon of flexor pollicis longus.

P. Carpal end of the metacarpal bone of the thumb.

[Illustration: Left hand, showing blood vessels, muscles and other
internal organs.]
Plate 18

PLATE 19.
AAA. Tendons of extensor digitorum communis; A*, tendon overlying that
of the indicator muscle.

B. Dorsal part of the annular ligament.

C. End of the radial nerve distributed over the back of the hand, to two
of the fingers and the thumb.

D. Dorsal branch of the ulnar nerve supplying the back of the hand and
the three outer fingers.

E. Radial artery turning round the carpal end of the metacarpal bone of
the thumb.

F. Tendon of extensor carpi radialis brevis.

G. Tendon of extensor carpi radialis longus.

H. Tendon of third extensor of the thumb.

I. Tendon of second extensor of the thumb.

K. Tendon of extensor minimi digiti joining a tendon of extensor
communis.

[Illustration: Right hand, showing blood vessels, muscles and other
internal organs.]
Plate 19

COMMENTARY ON PLATES 20 & 21.

THE RELATIVE POSITION OF THE CRANIAL,
NASAL, ORAL, AND PHARYNGEAL CAVITIES, &c.

On making a section (vertically through the median line) of the
cranio-facial and cervico-hyoid apparatus, the relation which these
structures bear to each other in the osseous skeleton reminds me
strongly of the great fact enunciated by the philosophical anatomists,
that the facial apparatus manifests in reference to the cranial
structures the same general relations which the hyoid apparatus bears to
the cervical vertebrae, and that these relations are similar to those
which the thoracic apparatus bears to the dorsal vertebrae. To this
anatomical fact I shall not make any further allusions, except in so far
as the acknowledgment of it shall serve to illustrate some points of
surgical import.

The cranial chamber, A A H, Plate 20, is continuous with the spinal
canal C. The osseous envelope of the brain, cal