BASES OF UNKNOWN CONSTITUTION in 



Pituitary extracts bring about contraction of the uterus in the cat, 

 dog, guinea-pig, rat, and rabbit, in all functional conditions. Adrena- 

 line, on the other hand, in some of these species has a motor effect 

 on the pregnant uterus only and inhibits the non-pregnant organ. 

 The effect of pituitary extracts on the uterus can be shown both by 

 intravenous injection into the anaesthetised animal and by means of the 

 surviving uterus in a bath of oxygenated Ringer's solution. The 

 latter method, applied to the uterus of the young virgin guinea-pig, has 

 been worked out by Dale and Laidlaw [1912, i] to a process for 

 standardising pituitary extracts and has also been used more recently 

 by Fiihner [1913]. It has the great advantage over blood pressure 

 experiments that tolerance is practically absent. Dale and Laidlaw 

 find that o-J^- c.c. of an extract obtained by boiling infundibula with five 

 parts of water will produce almost maximal tonus of the uterus in a 

 bath of 250 c.c. Ringer solution. Since such an extract only contains 

 about O'6 per cent, of solids, this represents a concentration of little 

 more than cri mg. of solid matter per litre, most of it being inert 

 material. The pituitary active principle is therefore a very powerful 

 uterine stimulant, the activity being probably at least of the same 

 order as that of y@-iminazolyl-ethylamine. 



In addition to the above effects on plain muscle, pituitary extracts 

 bring about a profuse flow of urine and also greatly increased secretion 

 of milk. The diuretic action was discovered by Schafer in conjunc- 

 tion with Magnus and with Herring and was at first attributed to a 

 different substance from that causing the rise of blood pressure ; later 

 observers, however, consider that the active principle is the same in 

 both these cases. According to Houghton and Merrill [1908] 

 diuresis is merely a secondary effect of the rise in blood pressure and 

 is also brought about by injecting adrenaline. The galactagogue 

 action was first observed by Ott and Scott [1911] and has subse- 

 quently been described by Schafer and Mackenzie [1911], and Ham- 

 mond [1913]. For the effect on the mammary gland in the human 

 subject see Schafer [1913]. 



Vitamine, Oryzanine, Toruline. 



A polyneuritis, resembling the tropical disease beri-beri, can, as 

 Eykman discovered, be induced artifically in fowls by feeding them on 

 an exclusive diet of polished rice. The condition is due to the lack 

 of a substance present in the outer coating of the rice and removed in 

 the process of polishing. During the last year or two several attempts 

 have been made to isolate this curative substance from various sources. 



