ired bits of
information concerning it have been assembled and fitted together like
the fragments of a picture puzzle, as Cushing has so well put it. Here
and there pieces stick out, obviously out of place. The relations of
some of them to one another or to the whole design are not at all
clear. Parts appear to have been irrevocably lost, or not yet to have
turned up. Chance bystanders will select odd figures and articulate
them into a new harmony. Yet out of the jumble of fragments, a fairly
respectable insight has been gained in less than a half century.

The pituitary is cradled in a niche at the base of the skull which,
because of its form, is known as the Sella Turcica or Turkish saddle.
So situated, an operative approach to it is overwhelmingly difficult.
On the other hand, X-ray studies are favored. "Nature's darling
treasure" it might be called, since there has been provided a skull
within the skull to shelter it.

Under the most highly magnifying lenses of the microscope, three kinds
of cells have been distinguished. The anterior gland is a collection
of solid columns of cells, surrounded by blood spaces into which their
secretion is undoubtedly directly poured. A gelatinous material,
presumed to be the internal secretion of the gland, has, in fact, been
observed emerging from the cells into the blood spaces. The posterior
lobe, or gland, consists of secreting cells producing a glassy
substance which finds its way into the spinal fluid that bathes the
nervous system. The spinal fluid itself is a secretion of another
gland at the base of the brain, the choroid. Nerves and internal
secretion are associated here with a closeness symbolic of their
general relations.

From each portion of the gland (to stick to the accepted nomenclature
of speaking of the two glands as one) an active substance has been
isolated. Robertson, an American chemist, separated from the anterior
lobe a substance soluble in the fat solvents, like ether and gasoline,
which he christened tethelin. But P.E. Smith has shown that the active
material is soluble neither in boiling water nor in boiling alcohol,
the typical fat solvent. A number of facts favor the idea of the
anterior lobe cells as stimulants of growth of bone and connecting
and supporting tissues generally. From the posterior lobe, pituitrin,
believed its internal secretion, has been obtained in solution.

Pituitrin is a substance of many marvelous functions. In general, it
con