104 



Scientific Proceedings (49). 



in whom one superior cervical ganglion had been removed, either 

 on the right or on the left side, I have injected at various times 

 various doses of pituitrin — 1 c.c, 2 c.c. and 3 cc — through the 

 marginal ear vein. At no time did a dilatation of the pupil on the 

 operated side follow these injections, neither soon nor late. Both 

 pupils, however, and especially that of the eye on the operated side, 

 showed a constriction of short duration immediately after the in- 

 jection. 



Here we meet, then, with a definite difference between the 

 action of adrenalin and pituitrin which, in some cases, might 

 assist in the identification of the nature of the blood-raising prin- 

 ciple found to be present in some fluids. 



75 (684) 



Observations on the relation of carbon dioxide and oxygen to 

 the development of certain amphibian embryos. 



By A. M. BANTA. 



[From the Station for Experimental Evolution, Cold Spring Harbor, 

 Long Island, New York.] 



The following observations were made during the past two 

 seasons upon material kept for other purposes. 1 



Eggs of all the species mentioned below were placed when 

 fresh or in early cleavage in artesian water containing 1.32 per 

 cent, of CO2, the amount normal to large open ponds here being 

 only about 0.04 per cent. 



Amby stoma punctatum. — Development was at the normal rate 

 with no mortality of embryos traceable to the CO2 in the water. 

 The larvae likewise lived fairly well, though in many cases not so 

 well in the CO2 water as in pond water. 



Spelerpes bilineatus. — Cleavage and later development were 

 probably at the normal rate, but there was a large mortality 

 percentage in standing or running artesian water. The mortality 

 was less in standing water from ponds but thoroughly oxygenated 

 water comparatively free from CO2 was necessary to get the 

 highest percentage of developing embryos. 



1 Observations on Spelerpes, Rana pipiens (?), and Rana sylvatica were made 

 on material kept in collaboration with Dr. R. A. Gortner, of this station. 



