SEA-FISHERIES LABORATORY. 251 



of the Atlantic than on the Pacific Coast. Addition of small 

 amounts of alkali to the water of Pacific Grove, so as to bring 

 its alkalinity up approximately to the level of the water of 

 Wood's Hole, caused the parthenogenetic cleavage to increase. 

 This is in agreement with the much earlier discovery of Loeb 12 

 that slight additions of alkali aided parthenogenesis and 

 hastened cell-division. The same result on increased rate of 

 cell-division was obtained by Moore, Roaf and Whitley 5 in 

 fertilised eggs of Echinus esculentus. 



This suggests an interesting thought as to the chemical 

 causation of the outburst of animal life in the spring. It may 

 be that it is the slow increase in alkalinity of the sea-water 

 caused by the photo-synthetic activity of the increasing 

 daylight upon the algae which reacts upon the animal life and 

 causes increased cell division, as also that sexual activity (at 

 least in the lower forms) which produces the shedding of ova 

 and sperms. In any case it is quite clear that the increased 

 alkalinity of the spring will be favourable to parthenogenesis, 

 as also to cell-division after fertilisation. 



The earliest observations by the hydrogen-electrode 

 method upon the hydrogen-ion concentration of sea-water 

 appear to be those made by Cottrell upon the suggestion of 

 Loeb 12 in the water of San Francisco Bay. The experimental 

 difficulties of such an observation as pointed out lately by 

 Palitzsch are very great and were apparently not overcome by 

 Cottrell, who found sea-water less alkaline than the neutral 

 point (P H ,10- 701 ). 



The Danish observer, W. E. Ringer 13 , was the first to 

 overcome substantially most of the difficulties of the task 

 lying in the way of obtaining hydrogen saturation of the 

 electrodes and fluid without displacing carbon-dioxide, and so 

 in the process of determination altering the alkalinity. This 

 observer made a long series of observations of the water of the 

 North Sea, the Zuidersee, and Bommel-fiord, and found it to 



