1905.] Effects of Alkalies, etc., on Eggs of Echinus. 105 



ion, arises from the fact that the constituents of the protoplasm behave like 

 very weak acids or bases, and are affected by variations in hydrogen or 

 hydroxyl ions in a similar manner to coloured indicators. Very small 

 variations in ionic concentrations compared to those found in even dilute 

 solutions of free acid or alkali, will hence cause the constituents of the cell to 

 become almost completely associated or dissociated, and prevent the chemical 

 reactions from occurring which are necessary for the metabolism and life of 

 the cell. 



This is shown in our experiments by the very small amounts of either acid 

 or alkali which suffice to kill the cell. Within the limits at which life is still 

 possible, but at which the concentrations of the two ions are varied from the 

 normal, profound alterations occur both in the rate of growth, and in the 

 type of the cell divisions. 



In the case of malignant growths similar variations in hydrogen and 

 hydroxyl ions occur as shown by the absence of the acid in the gastric juice. 



It is from this point of view that we have studied the effects upon growth 

 and cell-division of the addition of acids or alkalies in small amounts to the 

 medium in which such processes are taking place. 



The problem before us is that of the effects upon the cell of variations in 

 the hydrogen and hydroxyl ion concentration, and for the purposes of such an 

 enquiry it is not neccessary to know what are the actual concentrations of the 

 two ions in normal plasma, nor to discuss which of these two magnitudes is 

 the greater. 



If alkali be added to plasma or to sea-water the concentration in hydrogen 

 ions will fall and that in hydroxyl ions will rise, and conversely on adding 

 acid a reverse change will take place. The experiments we have made show 

 the results of such changes upon cell growth and nuclear division. 



A number of other observers have drawn attention to irregularities in cell 

 growth and nuclear division induced by the action of foreign chemical 

 substances upon the dividing cells. 



Thus, 0. and E. Hertwig* and also Galleottif have shown that pathological 

 mitoses with irregular division in number and amount of the chromosomes 

 may be induced by such substances as quinine, chloral, nicotine, anti-pyrine, 

 cocaine, and potassium iodide. 



The derangements in division so produced closely resemble the pathological 



divisions described in cancer cells by Klebs/f Hansemann,§ and Galleotti.|| 



* ' Jenaische Zeitsch. f. Naturwissenschaft,' vol. 20, 1887, pp. 120, 477. 

 t ' Beit. z. path. Anat. u. z. allgeni. Path.,' vol. 14, 1893, p. 288. 

 \ ' Die allgem. Pathologie,' Fischer, Jena, 1899, Part 2, pp. 523, et seq. 

 § * Virchow's Archiv,' vol. 119, 1890, p. 299 ; vol. 123, 1891, p. 356. 

 || Loc. cit. 



