8 



Scientific Proceedings (93). 



fast as the original flow (100 per cent.)- In five cats the flow 

 became as fast (or even faster) as immediately after opening the 

 abdomen ; and in one of these five the flow was as fast as the ori- 

 ginal. The blood pressure rose slightly on section of the nerve 

 in eleven cats. The remaining three were those in which there 

 was little or no increase in flow. 



The fact that in these experiments the blood flow after section 

 of the sciatic nerve in shock is usually far below normal, and never 

 above normal, certainly does not support the assumption, now 

 current, that vaso-constriction is greater in shock than in normal 

 conditions of the animal. 



6 (1381) 



Experimental studies of plant pigments. 



By Benjamin Harrow and William J. Gies. 



[From the Biochemical Laboratory of Columbia University, at the 

 College of Physicians and Surgeons, New York.] 



This communication was confined to a report on studies of 

 (a) flavones, a group of yellow pigments, characterized by the 

 production, in their solutions, of intense yellowish-brown color on 

 the addition of ammonia, and of (b) anthocyanins, a group of red, 

 violet, or blue pigments, which, in solution, change to bluish- 

 green on the addition of alkali, and pink on the addition of acid. 



These pigments were obtained from tulips: flavone, from 

 "La Reine"; anthocyanin, from "Crimson King." Both varie- 

 ties of flowers were collected at the N. Y. Botanical Garden 

 through the courtesy of Dr. A. B. Stout. 



The chemical relationship of flavones and anthocyanins. — Whel- 

 dale and others believe that flavone is convertible into antho- 

 cyanin by oxidation. The Armstrongs regard this conversion as 

 due to processes of oxidation and reduction. Combes and Will- 

 statter consider that reduction alone effects the change. The re- 

 sults of our own experiments accord with the view of the latter 

 investigators. We find that active ("nascent") hydrogen re- 

 duces flavone to anthocyanin. The latter can be further reduced 



