D. Noël Paton

The thymus and sexual organs

IN 1904_051 I carried out some investigations on the functionis of the thymus in the guinea-pig, an animal from which the organ can be easily removed. I then came to the conclusions: 1st, that removal of the thymus has no influence on the rate of growth of the animal; 2nd, that it is accompanied by a more rapid development of the testes before sexual maturity is approached; and 3rd, that after this period, the growth of the testes is uninfluenced by the removal of the thymus. Hend erson2 had previously shown that in castrated cattle and guineapigs the thymus attains a greater size than in uncastrated animals. I suggested that there is a reciprocal action between these organs and that the thymus exercises an inhibitory influence on the growth of the testes. In discussing my previous results with Dr Cathcart he suggested that the more rapid development of the testes in young animals after removal of the thymus might indicate that the two organs had a similar stimulating influence upon the growth of the animal and that each might compensate for the removal of the other by undergoing hypertrophy. Such a view would also explain the large size of the thymus in castrated animals. To test this theory experiments have now been performed in which both thymus and testes have been removed from very young guinea-pigs and the rate of growth of these animals compared with that of normal animals. In order to check the results obtained, the effect of simple castration and of simple removal of the thynmus on the rate of growth has also been studied. These

Digestion leucocytosis: II. The source of the leucocytes1

IN a previous paper(1) we found that the total number of leucocytes in the circulating blood rises during digestion and reaches a maximum in about four hours after food. This leucocytosis is not affected by removal of the spleen. The increase comprises a lymphocytosis and a polymorphonuclear leucocytosis but the eosinophils show very little change. The number and varieties of white cells in corresponding mesenteric veins and arteries during digestion are similar, and resemble those in the general circulation.

The effect of adrenalin on sugar and nitrogen excretion in the urine of birds

IN a previous paper, I recorded observations on rabbits and dogs which seemed to prove that the glycosuria induced by the subcutaneous in.jection of adrenalin is essentially a true diabetes. I showed that it is the result of a glycsamia, that it is produced even when the stored carbohydrates have been cleared out of the body by pbloridzin, and that it is accompanied by the disturbances in the distribution of nitrogen in the urine which occur in diabetes. Herter2 has adduced evidence to show that adrenalin acts through the pancreas. His conclusion was based upon the observations that(a) intra-peritoneal injection of adrenalin acts very powerfully in causing glycosuria, (b) painting adrenalin on the pancreas causes glycosuria, (c) the application of other reducing substances such as cyanide of potassium to the surface of the pancreas causes glycosuria. It is however possible that the substance may be absorbed by the pancreatic blood and may act directly on the liver, although Herter states that the direct injection of adrenalin into that organ did not produce so marked a glycosuria.

Digestion leucocytosis in normal and in spleenless dogs1

AN increase in the number of leucocytes in the circulation during digestion is now a familiar observation, but the exact nature of the leucocytosis and its true meaning have never been satisfactorily demonstrated, nor has the question of whether the spleen plays any part been considered. Hofmeister(l) described an increase in the lymphocytes of the intestinal wall along with the absorption of the peptones in proteid digestion. Pohl (2) externded these observations and found a considerable increase in the number of white cells in the blood generally, after a proteid diet and at the same time a relative diminution of the mononucleated cells. On comparing the number of leucocytes in corresponding mesenteric veins and arteries a large excess of white cells was found in the veins during digestion. The inference from these observations seems to be that the leucocytosis is due to an increase in the number of polymorphonuclear cells, and these, according to Pohls observations, are derived from the intestinal wall. Several authors, e.g., Cabot (3, class the increase of white cells dutring digestion as a polymorphonuclear leucocytosis, while others, e.g., Ehrlicb and Lazarus(4), state that the relative proportion of polymorphic cells and lymphocytes does not vary. Ascoli (5) describes digestion leucocytosis, which he considers as probably due, like the leucocytosis of infection, to a chemiotactic influence.

Further Investigations on the Life-History of the Salmon in Fresh Water.

In the “Report on Investigations into the Life-History of the Salmon in Fresh Water,” published in 1898, the changes which the fish undergoes between the months of May and November were dealt with, but there was no material available to enable the observations to be extended throughout the remaining five months of the year, from December to April.

On the modifications of the metabolism produced by the administration of diptheria toxine

IT is now almost universally admitted that a high temperature is not an essential part of infective febrile processes, but that it, like the other symptoms, is one of the results of the toxic action of the products of micro-organisms, and that it is caused in the first instance by diminished heat elimination. In the later stages of some fevers increased heat production undoubtedly plays a part. A vast number of observations on the influence of these infective processes on the economy have been recorded, but a study of such a work as von Noordens Pathologie des Stoffwechsels, shows how much yet remains to be investigated before we can comprehend the modifications in the chemical processes in the body induced by these conditions. In attempting to gain a knowledge of such changes we have to depend largely on the study of the alterations in the excretions-in the expired air and in the urine. So far the study of the respired air has yielded more constant and conclusive results than the examination of the urine. For in the case of the latter excretion, when we come to compare the mainy different observations which have been recorded, the discrepancies which manifest themselves are so evident that it is difficult to draw any satisfactory conclusions. It appeared to us that a careful and systematic study of the effect

Contributions to the study of the metabolism of phosphorus in the animal body

1. Preliminary. 2. The Absorption and Excretion of Phosphorus. i. General considerations and previous work. ii. Normal intake and output of phosphorus in dogs on mixed diet, and in goat. iii. Subcutaneous injection of phosphate of soda. iv. Influence of milk secretion. 3. The Distribution of Phosphorus in the Milk of the Goat. 4. The Influence of the Administration of Glycerophosphate of Lime in the Excretion of Phosphorus. 5. General Conclusion. 6. Appendix-Methods and Analyses.