Already, recent scientific investigations and the results obtained therefrom have begun to turn the attention of medical authorities to the activities of two very small organs situated in the mid-brain and known as the _pineal gland_ and the _pituitary body_. These organs, and especially the _pineal gland_ hitherto supposed to be a vestige of the past, are now beginning to be recognized as rudimentary organs belonging to the future evolution of humanity. Dr. CHARLES DE M. SAJOUS, who is an authority on the _pituitary body_, believes that it has no active internal secretions but is an "epithelio-nervous organ" which controls, through nerves leading to the adrenals and thyroid bone, the processes of general oxygenation, metabolism and nutrition. Little is known of the functions of the pineal gland except that it is an ovoid, reddish organ attached to the posterior cerebral commissure projecting downward and backward between the anterior pair of the _corpora quadrigemina_. It is otherwise known as the "_conarium_" the "_pinus_" or "_epiphysis_." Situated at the base of the brain, it is held in position by a fold of the _pia mater_ while its base is connected with the cerebrum by two pedicles. It contains amylaceous and gritty, calcareous particles constituting the brain sand. There are, however, marked structural resemblances between the _pineal gland_ and the _pituitary body_ and their formation is perhaps the most interesting feature of the development of the _thalamencephalon_ or mid-brain. The _hypophysis cerebri_ or _pituitary body_ is a small, ovoid, pale, reddish mass varying in weight from five to ten grains and situated at the basal extremity of the brain in a depression of the cranium known as the _sella turcica_, a configuration very much like a Turkish saddle in shape. It is a composite, ductless gland and consists of two divisions, an anterior and a posterior, connected by an intermedial portion--all of which are attached to the base of the cerebrum by the _infundibulum_. The anterior lobe is larger than the posterior and very vascular, springing in its development from the buccal cavity of the embryo; the posterior lobe is situated in a depression of the anterior and is a brain-process. The _pituitary body_ itself is lodged in a cavity of the _sphenoid_ bone called the _pituitary fossa_. This is a most remarkable position, for the reason that the _sphenoid, or wedge-shaped_, bone which lies at the base of the skull articulates from behind with the occipital and in front with the _frontal_ and _ethmoid_ bones and by lateral processes with the _frontal_, _parietal_ and _temporal_ bones. From this position it binds together all the bones of the cranium, and moreover, articulates with many bones of the face. It is upon the upper surface of the _sphenoid_ bone which occupies such a prominent and commanding position in the cranium, in a deep depression, that the _pituitary gland_ is located.