THE MECHANISM OF EXOPHTHALMOS

"Apart from gross neoplastic and inflammatory lesions of the orbit, the mechanism of exophthalmos is still little understood." This curious statement emanates from the textbook of Brain,¹ one of the leading members of the distinguished London school of neurologists; nevertheless the mechanism of exophthalmos is well understood, though the knowledge would seem to be poorly disseminated. This fault must be laid in part at the door of the anatomists, who, though describing accurately enough the external ocular muscles controlled by the third, fourth and sixth cranial nerves, have failed to teach the known anatomic knowledge in regard to the antagonists of these muscles, which are unstriated and controlled by sympathetic nerves. The physiologists, too, must share the blame; for what explanation do they offer of the delicately balanced muscular mechanism that results in normal binocular vision and in diplopia when this mechanism is disturbed? Are we to believe that