Studies in intracranial physiology & surgery : the third circulation, the hypophysis, the gliomas / by Harvey Cushing.
- Harvey Williams Cushing
- Date:
- 1926
Licence: In copyright
Credit: Studies in intracranial physiology & surgery : the third circulation, the hypophysis, the gliomas / by Harvey Cushing. Source: Wellcome Collection.
85/168 page 69
![of the gland, the tadpole not only becomes retarded in its growth but remains pale or albinoid owing to contraction of its cutaneous pigment cells [Adler (1914) ; Smith (1916) ; Allen (1917)].* These pale animals serve as a most delicate indicator for posterior-lobe (pars intermedia?) secretion, for on its injection in minute amounts the melanophores expand and the animal acquires the normal colour. This melanophore reaction to posterior-lobe extracts has not as yet, so far as I am aware, been utilized as a test for the presence of this substance in the cerebrospinal fluid. But whatever future studies may bring forth in this respect, it may suffice to say that the posterior lobe is a unique organ surrounded by an investment of indolent-appearing epithelial cells, seemingly under the direct control of nerve fibres, and that stimuli of one sort or another cause these cells to divide and bud off directly into the loose tissue reticulum wherein they undergo some sort of amorphous transforma¬ tion as they progress towards the stalk and the infundibular cavity. At this point they not only have the appearance of passing between the ependymal cells into the ventricle, but when this pathway is experimentally occluded, the gland be¬ comes packed with the transforming cells and their secretory products. With the exception of the last step in this process, our views I believe coincide with those of most others who have been interested in the subject. All agree that we are dealing with a secretion of extraordinary potency which accumulates in the loose tissue spaces of a poorly vascularized and unique organ. These tissue spaces obviously radiate towards the * These observations have been greatly amplified by L. T. Hogben who has studied the effects of hypophysectomy on adult amphibians (The Pig¬ mentary Effector System. Edinburgh, 1924).](https://iiif.wellcomecollection.org/image/b29929209_0085.jp2/full/800%2C/0/default.jpg)
