The hypophysis cerebri, or pituitary body, is currently described as being composed of two lobes; the anterior, larger lobe, is embryologically described as arising from the epithelium of the mouth cavity, its glandular structure resembling in many respects the structure of the thyroid gland. It is stated by Haller1 that it possesses an incomplete system of ducts that open between the meninges. In a recent article, W. H. Howell2 maintains that, properly speaking, the term hypophysis cerebri should be restricted to this lobe. This significance is now given the term by most morphologic writers, but human anatomy commonly includes the so-called posterior lobe as well.
The posterior lobe lies upon and is partially covered in by the hypophysis proper, and it will be recalled that it is connected by a stalk to the infundibulum, and that embryologically it is regarded as an outgrowth of this part of the