102 INFLUENCE OF VARIOUS AGENCIES 



and calcium ions, and recognised it though not by name as ionic 

 activity, when yet the ionisation theory had obtained but little 

 credence. 



Ringer's experiments upon the effects of acids and alkalies 

 were, however, confined to the action of these in maintaining 

 physiological activity, and it remained for Loeb to demonstrate 

 upon the fertilised eggs of the sea-urchin that the rate of growth 

 is appreciably increased by very minute amounts of alkali added 

 to the sea-water, larger amounts stopping the growth entirely. 



The writer, led to the subject from its relationship to malignant 

 growth, by the fact that the secretion of the acid in gastric juice 

 was suppressed or diminished, and the alkalinity of the blood 

 increased in cancer, has recently carried out, in conjunction with 

 H. E. Roaf and E. Whitley, a series of observations on the effects 

 of acids and alkalies, and of acids and alkaline salts upon the 

 rate of growth and character of the cell division in the fertilised 

 eggs of Echinus esculenlus. 



It was found that a mere trace of added sodium hydrate, 

 viz. Ytj 1 ^ normal, 1 increased markedly the growth even in the 

 earlier stages, and not merely after one or two days, as Loeb had 

 previously found, while the addition of half as much more sodium 

 hydrate practically stopped the growth altogether, the cells not 

 proceeding beyond the four-cell stage. Addition of double the 

 quantity, -g^ normal, stopped the growth entirely. Addition of 

 hydrochloric acid slowed the growth from the beginning, and 

 at - g l^ normal the growth was stopped entirely, all the cells 

 remaining in the single-cell stage. 



The action of alkaline and acid salts, such as the phosphates 

 and carbonates, corresponding to their lessened concentration in 

 hydoxyl or hydrogen ions, were less effective, and these salts had 

 to be added in greater concentration. 



In addition to the alteration in rate of growth, it was found 

 that the addition of alkali, in more than the minimal concentra- 

 tion of Y^Q-Q normal, led to marked irregularity in the size and 

 shape of the cell, and to irregular nuclear division. In the large 

 undivided cells, multiple nuclei were found, and many division 



1 That is, one c.c. of - alkali per 100 c.c. of sea- water : this amounts to 



only one part by weight of sodium hydrate in 25,000 parts by volume of sea- 

 water. 



