328 LOUISE A. ANDERSON. 



alkaline solutions on the development of the teleost Pleuronectes. 

 The fertilizability of Arbacia and Asterias eggs is increased by 

 short exposures to alkaline sea-water according to Smith and 

 Clowes ('24). Accelerations of activity by alkaline solutions 

 have been observed by Dale ('13) in Paramecium and by Gray 

 ('24) in the frontal cilia of Mytilus edulis. 



Direct measurements of respiratory rate in alkaline solutions 

 have yielded diverse results. In certain bacteria Brooks ('21, '22) 

 noted the maximum rate of carbon dioxide production at or near 

 neutrality with progressive decline in the rate with increasing 

 alkalinity. The respiratory rate of the mold Penicillium chryso- 

 genuin is decreased 60 per cent, upon increasing the alkalinity of 

 the medium from neutrality to pH 8.8 with NaOH (Gustafson, 

 '20). According to Loeb and Wasteneys ('n) the rate of 

 oxygen consumption of Arbacia eggs is increased 20-30 per cent, 

 by raising the alkalinity of the sea- water with NaOH to pH 10.0 

 and increased 100 per cent, by raising it from pH 10.0 to 10.9. 

 Similar results were obtained when ammonia was used. Thun- 

 berg ('09) found a decrease in the carbon dioxide production of 

 excised frog muscle in solutions of NaOH, Ca(OH) 2 , and 

 Mg(OH) 2 . Waldbott ('24) noted a slight acceleration of the 

 respiratory metabolism of humans after the ingestion of alkaline 

 solutions. The carbon dioxide production of tadpoles is increased 

 in solutions of potassium and sodium hydroxide, but the rate 

 of regeneration of the tail is retarded (Jewell, '20) ; Jewell re- 

 garded the increased respiratory metabolism as of a destructive 

 nature. 



From this review of the literature it is evident that both re- 

 tardation and acceleration of biological processes result from ex- 

 posure of organisms to alkaline solutions. In general, in the case 

 of animal materials, an acceleration of growth and development 

 and of respiratory metabolism in alkaline solutions has been found 

 in the majority of cases. 



OXYGEN CONSUMPTION EXPERIMENTS. 



i. Methods. The experiments consisted in determining the 

 rate of oxygen consumption of planarians first in normal water 



