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IN 1917, at a time when the existence of the various hormones of the pituitary was not established and none had been isolated, one of us (C. F.) advanced a working hypothesis on the relationship of this gland and neoplastic disease. The necessity for further research into the effect of the pituitary gland (anterior lobe) on cancer was pointed out. At the time it was known that adenomas of this gland produced abnormalities in children and young adults; it was therefore postulated that in later life, when gigantism and acromegaly were no longer possible, increased activity of the pituitary gland might be responsible for the production of tumours (Funk, 1917). For a long time and for obvious reasons it was impossible to put this hypothesis to a test. Thanks to the classical work of Evans, Li and Simpson (1948) we now have the necessary tools for preliminary and systematic appraisal of the importance of various hormones of the anterior pituitary in tumour growth.The purpose of the work reported in this paper was to test the effect of various anterior pituitary and related hormones upon the growth of implanted tumours in hypophysectomized rats. As a supplement to this work we also dealt with the removal of certain organs (mainly glands of internal secretion) on the rate of growth of a transplanted rat tumour in otherwise intact animals. While there is no doubt that studies on this subject have already been made, it appears doubtful whether a systematic study was ever made of the effect of the removal of these organs upon the growth of one particular tumour. As an addendum we have also investigated the influence of alloxan diabetes upon the tumour. MATERIALS AND METHODS.Hypophysectomy experiments.The hypophysectomized and normal rats, Sprague-Dawley strain, were supplied to us via air freight by the Hormone Assay Laboratories, Inc., Chicago, Illinois. The tumour used was the Walker Carcinosarcoma 256. As a criterion of completeness of hypophysectomy we have used the test established by CortisJones, Crooke, Henley, Morris and Morris (1950), and have eliminated from our experiments those rats not receiving gonadotropin whose testes weighed over 500 mg. In order to ascertain the relative purities of the hormones used in this investigation the following organs were excised and weighed: the thyroids, the adrenals, the testes and the spleen.The animals were divided into groups after tumour implantation, which

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FACTORS INFLUENCINGport inferred that muscle fasciculations result from a direct action of the blood on the muscle fibers, Under the condi tilons of these experiments, it is evident that the fasciculations and tonic spasms occasioned by alkalosis and hypocalcemia can occur as the result of spontaneous iterative discharges arising in peripheral motor nerve fibers or their terminations in the motor end plates. These results cannot, of course, preclude the possibility of the participation of neurons within the central nervous system, or of sensory neurons in spinal and perhaps even supraspinal reflex arcs. In fact, there is considerable evidence that sensory fibers also are irritated and discharge repetitively in human tetany ( 2 ) . However, our results strongly suggest that activation of peripheral motor nerve fibers or terminations account for the motor manifestations of tetany whether caused by an elevation in blood pH or a reduction in ionized blood calcium. This view is supported by Kugelberg's( 15) finding in one human subject with inveterate hypocalcemic tetany that impulses occurring in the fourth interosseous muscle of the hand and recorded electromyographically continued unaltered after apparently effective procaine block of the ulnar nerve at the elbow.Sumnaar.v. 1. Tetany was produced acutely in eleven cats and one dog with solutions of sodium bicarbonate, sodium carbonate and a phosphate buffer administered by venoclysis. Fasciculations and tonic spasms involving especially the head and forelimb musculature characterized this form of tetany. Clonic spasiiis were were not seen in anesthetized ani-SHAY RAT VLCERATION 333 mals. 2. Section of the hypoglossal nerve did not significantly influence the fasciculations oi the tongue musculature. Section oi the brachial plexus did not significantly inhence the fasciculations or tonic spasms of the iorelimb musculature. 3. Paralvtic doses of dtubocurarine blocked all motor maniiestations of tetany. 4. It was concluded that all of the motor phenomena characterizing alkalotic and hypocalcemic tetany could result from the spontaneous iterative discharges occurring in peripheral motor nerye fibers or their terminations.In our experience, the incidence of ulcers paper. Recently, Madden ef QZ. ( 1) in a critiin the Shay rat varied from 100% to 25%. cal study of the Shay procedure concluded There are no apparent reasons for this varia-that the method is valuable for the study oi tion, and some of the complicating, but sig-gastric secretion and of less value ior the study nificant, observations are recorded in this of the ulceration mechanism. We have used

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