o 



84 SUMMARY OF CURRENT RESEARCHES RELATING TO 



c. General. 



Marine Plankton around South End of Isle of Man.*— W. A. 

 Herdraau, Andrew Scott, and H. Mabel Lewis refer briefly to the inten- 

 sive study of the plankton of a small area near the centre of the Irish 

 Sea. The study has been continued for ten years, and 5116 samples 

 have been taken, of which 496 were in 1916. The spring maximum for 

 the total plankton in 1916 was in June, a month later than in 1915 and 

 several previous years. The maxima of the leading groups succeeded 

 one another in the usual order, as follows : — In May, the Diatom 

 maximum ; in July, the Dinoflagellate maximum ; in September, the 

 Copepod maximum. The monthly average number of Dinoflagellates 

 for July was 148,241 ; the actual largest number was ?)16,400 on July 6, 

 of which 300,000 were Geratiimi tripos. The monthly average number 

 of Copepods for September was 57,616, and the largest haul yielded 

 118,524 on September 25. 



Increase of Erythrocytes after Exposure to Carbonic Acid.f — 

 Dorothy Dufton exposed rabbits to atmospheres containing an unusually 

 high percentage of carbonic acid in the air, and observed in a few days 

 (six) a marked increase in the number of erythrocytes. In whatever way 

 the carbonic acid may act, which requires further investigation, the 

 results suggest that any factor, such as violent exercise, which produces 

 a temporary rise in the concentration of carbonic acid in the blood, will 

 produce a corresponding formation of fresh corpuscles. 



Experiments in Regard to the Pituitary Body.| — W. Blair Bell 

 finds that the removal of the pituitary body in dogs causes death in a 

 few hours. It is the removal of the anterior part which is particularly 

 fatal. Partial removal of this part may cause genital atrophy. Neither 

 partial nor complete removal of the posterior part causes any symptom. 

 The secretion of the pars nervosa is neither necessarily beneficial nor 

 essential to life. Clamping and separation of the infundibular stalk, by 

 interfering with the blood-supply and so causing degeneration in the 

 cells of the partes anterior and intermedia, lead to the condition known 

 as dystrophia adiposo-genitalis. The pituitary body ap])ears to be one 

 organ and not two ; and the essential and beneficial secretion is taken 

 up by the blood-stream, as in the case of the other organs of internal 

 secretion. 



Effect of Thyroid on Suprarenals.§ — P. T. Herring finds that small 

 quantities (()"2--0'5 grm.) of fresh ox-thyroid administered daily to 

 white rats increases the size and weight of the suprarenals both in young 

 and adult animals. In three or four weeks there was an increase in 

 weight of from 76 to 78 p.c. above the normal. Both cortex and 



* Eeport Lancashire Sea Fisheries' Laboratory. No. 25 (1917) pp. 28-30. 



t Proc. Physiol. Soc, in Journal of Physiology, li. (1917) Nos. 1-2, pp. v-vi. 



t Quart. Journ. Exper.- Physiol., xi. (1917) pp. 77-126 (57 figs.). 



§ Quart. Journ. Exper. Physiol., xi. (1917) pp. 47-57. 



