176 CARNEGIE INSTITUTION OF WASHINGTON. 



sense-organ be not present, and in addition he found that if sense- 

 organs be present the medusa starves more rapidly than if they be 

 absent. Thus the general metabolism of the medusa is under the 

 control of its nerve-centers. 



Professor Gary also continued liis study of the growth-rate of 

 gorgonians, and his remarkable discovery that the gorgonians con- 

 tribute more limestone to the Tortugas reef-flats than do the stony 

 corals is so unexpected that he should be given an opportunity to visit 

 the Pacific reefs in order to determine whether this be a general or 

 merely a local condition. In accord with Vaughan's intensive studies 

 of the Florida- West Indian region, this discovery of Professor Gary's 

 tends to beUttle the coral factor as a constructive agent in the 

 building up of Atlantic coral reefs. Undoubtedly, however, the corals 

 are a more important factor in the Pacific than in the Atlantic, and their 

 effect in this greater ocean should be quantitatively determined. 



Professor George A. Hulett, of Princeton University, was so kind as 

 to direct Mr. John H. Yoe in the distillation of 144 hters of water by 

 the well-known Hulett method, using the still in the Princeton labora- 

 tory. This water had a hydrogen-ion concentration, due to GO2, of 

 between 0.8 to 1.0 X 10~^ and it was sealed in Hter flasks of Pyrex 

 glass, and thus transported to Tortugas to be used in physiological 

 work. This water was used by Mayer to determine the rates of nerve- 

 conduction in Cassiopea when placed in sea-water diluted with distilled 

 water. The results suggest that sodium and calcium unite to form a 

 chemical combination with some proteid element. Na, Ga, and K 

 are the only cations necessary for nerve-conduction; Mg being nearly 

 as inert as distilled water. The ion-proteid concerned in nerve-con- 

 duction has a high-temperature coefficient of ionization. The reaction 

 is probably accelerated by an enzyne (Harvey, 1911). Recently Pro- 

 fessor Ralph S. Lillie has stated in the American Journal of Physiology 

 that the rate of nerve-conduction probably declines in the same ratio as 

 the conductivity in diluted sea-water, and tests made by us, using Kohl- 

 rausch's method with Tortugas sea-water, showed that this appears 

 to be true, but it is untrue for changes in temperature of the sea-water, 

 the rate of nerve-conduction augmenting 2.5 times as rapidly as does 

 the electrical conductivity as the water is heated. The rate of nerve- 

 conduction, however, does not depend on the electrical conductivity 

 of the sea-water, for it makes no significant difference whether the sea- 

 water be diluted with distilled water or with 0.4 m. MgGl2. 



Professor A. J. Goldfarb conducted an important study of the effects 

 of aging upon the ability of the sperm of individual male echini to 

 fertilize the eggs of individual females. His report (pages 201-203) will 

 indicate the character of his results. Unfortunately, the heavy storm 

 of July 4 to 6 so agitated the echini over the Tortugas reefs that their 

 eggs were rendered useless and the work was interrupted at a most 



