MAMMALIA— PHYSIOLOGY 449 



Dr. Oliver Kamm reported^ (December, 1928) the isolation of 

 two hormones from the posterior lobe of the pituitary. The alpha 

 hormone is effective in obstetrics, contracting the uterus, while the 

 beta hormone raises blood pressure and also controls the excessive 

 output of water and its utilization in the body tissues. Fleshy 

 people (the physiological wets) are extremely sensitive to the 

 action of the beta hormone, while slender scrawny ones (the physio- 

 logical drys) quickly return to normal after the administration of 

 this hormone. Both hormones act immediately to increase the 

 sugar of the body and thus offset an overdose of insulin. 



References on the Endocrines 



Barker, L. F. 1925. Endocrinology and Metabolism. D. Appleton 



and Co. 

 Cooper, E. R. A. 1925. The Histology of the More Important Human 



Endocrine Organs at Various Ages. Oxford University Press. 

 DoDDS, E. C, AND Dickens, M. A. 1925. The Chemical and Phys- 

 iological Properties of the Internal Secretions. Oxford University 



Press. 

 Falta, Wilhelm, and Meyers, M. K. 1923. Endocrine Diseases. 



P. Blakiston's Son and Co. 

 Sharpey-Schafer, E. The Endocrine Organs. Part I, 1924, and Part 



II, 1926. Longmans, Green and Co., Ltd. 

 Vincent, Swale. 1925. Internal Secretion and the Ductless Glands. 



Physicians and Surgeons Book Co. 



The Circulatory System. — The blood vessels are a system of tubes 

 completely closed except where the lymphatics open. In one place 

 the system is dilated into a large complexly formed rhythmically 

 contractile organ, the heart, which is the central portion of the 

 circulatory system and, according to the studies of O. C. Glaser 

 (193 1), works basally against the resistance offered by the system 

 of enclosed tubes. According to the author, objections may be 

 offered to this view because of its apparent simplicity which does 

 not seem to take account of the numerous influences which may 

 temporarily modify the tubal resistance. There are several kinds of 

 channels in which blood flows: (i) Vessels taking blood from the 

 heart — arteries. (2) Vessels taking blood to the heart — veins. (3) 



2 Kamm, O. Science, vol. 67, p. 199, 1928; J. Am. Ch. Soc, vol. 50, p. 573; 

 Science, vol. 69, p. 85, 1929. 



