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radical surgical operation is still the method ofchoice in the early and hopeful case. In the latercase, where the glands are involved, some supple-mentary post-operative therapy is indicated, and theyregard irradiation with X rays as the most certainof the measures available for this purpose.

ADDISON’S DISEASE

THE Therapeutic Trials Committee of the MedicalResearch Council are arranging an inquiry into thevalue of extracts of suprarenal cortex in the treatmentof Addison’s disease. The work will be done on theCommittee’s behalf by Prof. T. R. Elliott (UniversityCollege Hospital, London), Dr. Robert Hutchisonand Dr. S. Levy Simpson (London Hospital), Dr. J. F.Wilkinson (Royal Infirmary, Manchester), and Prof.D. Murray Lyon (Royal Infirmary, Edinburgh).As it is desired to admit to these hospitals enoughpatients for the inquiry as soon as possible, theCommittee asks consultants and practitioners havingsuitable cases of Addison’s disease under their careto communicate with one or other of the physiciansnamed above.

HERNIA CAUSED BY ŒSTRIN

IN the course of experiments on ketohydroxy-oestrin which are in progress at the Cancer Hospital,London, the surprising fact has been brought to

light that mice treated with this substance tend todevelop scrotal hernia. The scrotal pocket in micecommunicates very freely with the general peritonealcavity, without any attempt at formation of a

funicular canal, but in the ordinary way there is notendency for hernia to occur, and among 580 micenot treated with oestrin not a single case of herniawas observed ; nor, in the healthy animal, can thegut be protruded into the scrotal pocket by pressureapplied to the abdominal wall. Yet of 49 mice treatedwith oestrin 19 developed hernise, unilateral or

bilateral, within 6-10 weeks of administration of thefirst dose. The cestrin was applied either by paintingit on the skin or by subcutaneous injection. Mr.Harold Burrows, in his account of these observations,!points out that there is adequate evidence thatcestrin applied to the non-epilated skin of the backis absorbed in amount sufficient to keep the femalemouse in a constant state of oestrus, and to cause thevaginal canal to become blocked with a mass ofkeratinised epithelium. There seems, therefore, noreason to doubt the fact of the absorption of thesubstance in the male mice in effective quantity.Two known effects of oestrin administration to themale mouse which might have some bearing on theappearance of hernia are atrophy of the testis andprostatic enlargement. Both, however, are lateeffects, whereas hernia occurs early. Moreover,rats in which testicular atrophy has been produceddo not develop hernia. Prostatic obstruction in themice eventually progresses so far as to producedistension of the bladder with overflow and hydro-nephrosis, so that it seems, at first sight, that thestraining efforts during micturition might be sufficientcause for the hernia. But these effects have not beennoted earlier than the fifth month after the firstdose of oestrin, whereas hernia is observed as earlyas 35 days after the beginning of treatment. Inone experiment, 11 of 13 mice alive 47 days after thefirst dose had herniae. Burrows explains the pheno-menon as an effect of oestrin on the tonicity of themusculature controlling the entrance to the scrotalpocket. He suggests that relaxation of these muscles

1 Brit. Jour. Surg., January, 1934, p. 507.

may be analogous to the relaxation of the pelvicmuscles and ligaments during the later stages of

pregnancy in the presence of large quantities of

circulating cestrin.

BLOOD REGENERATION

A RECENT discussion1 on blood regeneration in

experimental anaemia and in anaemias occurring inclinical practice showed that much is now knownof the normal response occurring after haemorrhageor when a deficiency of essential factors is made

good in deficiency dysh2emopoietic anaemias. Themechanism by which certain factors inhibit haemo-poiesis is still unknown. Dr. Hamilton Fairleydescribed a series of important observations uponregeneration occurring in tropical anaemias, whichillustrate our ignorance only too clearly. Forinstance, in anaemia due to amcebic abscess of theliver, reticulocytosis and blood regeneration followthe administration of emetine ; and the disappearanceof parasites, after treatment with quinine or atebrin,both in naturally infected cases of malaria and in

syphilitics artificially infected, is followed by a

reticulocytosis proportional to the degree of theanaemia. He concludes that once the cause of theanaemia has been dealt with, in the absence of otherinhibitory factors, some conservative mechanismautomatically stimulates the erythroblastic tissue ofthe bone-marrow and results in a rapid blood

regeneration. Why removal of the infective agentshould immediately result in such regeneration is notclear. Dr. Janet Vaughan pointed out that in thedeficiency dyshsemopoietic anaemias sepsis possessedthe same inhibitory power ; in the presence of infectionenormous doses of potent material are without effect.She also discussed the inhibitory action of achlor-

hydria, failure of intestinal absorption, and of arterio-sclerosis, which are as little understood as the effectof sepsis. Prof. A. E. Boycott described results ofexperiments which suggest to him that the bone-marrow learns from experience. He found thatblood regeneration following a second haemorrhagein an animal was more rapid than to a first haemor-rhage. This is possibly due to the fact that the stimu-lating action of the first blood loss has increased theamount of active bone-marrow. He put forwardthe suggestion that if fresh red cells are likely to beneeded-for instance, in climbing Mount Everest-the rational preparation is a course of bleedings togive the marrow experience and practice. It wouldbe of interest to know at what point depletion ofthe body’s store of hsemopoietic factors wouldcounteract the increased amount and experience ofthe bone-marrow.

COMFORT IN THE TROPICS

CONSIDERING its importance, little experimentalwork has been directed towards the reduction ofdiscomfort from heat in the tropics. Those who livein these regions should therefore welcome the verypractical suggestions made by Dr. G. P. Crowden inour issue of Jan. 6th. The principles involved aresimple. Since the classical experiment of Franklinwith cloths of different colour on snow, we haveknown that black surfaces absorb most heat andwhite least. But the inner surface of a container

may radiate the heat it has absorbed from the outside,and it is also known that a bright metallic surfaceradiates very little heat compared to other surfaces.In addition, the conductivity of air is very low :thus, if the thermal conductivity of still air be taken

1 Royal Society of Tropical Medicine and Hygiene, Feb. 15th.