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concentration of soda dissolved in it. If sea water contains no 

 excess of alkali at all, this development will not occur. The 

 alkali alone — soda alone — will not cause development unless the 

 concentration is raised. Therefore we have two factors — concen- 

 tration, and what we call alkalinity. The question arises "What 

 is the significance of these two factors?" What part does each 

 play in the result observed? That can now be very simply 

 answered. All that the alkalinity of the sea water does is to 

 accelerate the process. As we increase the quantity of alkali 

 in the sea water the successive cell-divisions occur more rapidly. 

 In the total absence of alkali they would probably occur some 

 time, but perhaps not for centuries, and in the meantime bacteria 

 would get in, and the cell in various ways would meet the fate 

 which we believe to be the fate of all living material before there 

 had been time for the first cell division to occur. In what way 

 does the alkalinity increase the velocity of the cell divisions? It 

 does so by accelerating the rate at which the combustions go on 

 within the cell — oxidations. . Oxygen is being used up by the cell 

 during these divisions. When that is being used it means that 

 something is being burnt up. When anything burns — a candle, 

 a fire, or ourselves — oxygen is used up in the process. If we 

 deprive the cell of oxygen, or diminish the amount of oxygen 

 supplied to it, these divisions cannot take place in the presence of 

 any quantity of alkali, or of any concentration of sea water. 

 It is a familiar fact to the physiological chemist that alkali 

 increases the velocity with which oxidations occur in animal 

 fluids, and the function of the alkali in these processes is almost 

 certainly that of accelerating the oxidations necessary for cell 

 divisions. This factor of the alkalinity of sea water was over- 

 looked in the first stages of the investigations, and from that 

 many curious mistakes arose. In the first place Professor Loeb 

 did these experiments at Wood's Holl, on the Atlantic coast. 

 He was perfectly successful with thousands of them. Then 

 when he came out to Pacific Grove, on the Paci- 

 fic coast, he tried to repeat the experiments, and 

 failed completely. At first he was very much puzzled 

 and worried. It was only after a whole summer's 

 investigation that he found that the Pacific Grove sea water was 

 less alkaline than that of Wood's Holl. Whereas the latter water, 

 concentrated, would cause artificial fertilization by itself, to the 

 Pacific Grove water he had to add some alkali. That mistake has 

 been repeated more recently in Plymouth, England, where they 

 have failed for years to get Loeb's results. Dr. Loeb went 

 across to Europe a year ago, and, passing through Plymouth, 

 found them in this dilemma. He at once suggested the addition 

 of a little alkali to the sea water, and immediately they were- 

 able to repeat all his experiments with complete success. This 

 method of artificial fertilization was not completely successful 

 in that it did not absolutely imitate natural fertilization. The 

 clear membrane around the outside of the dividing cells which is 

 characteristic of natural fertilization was not produced. It was 

 not until 1905 that Professor Loeb succeeded in finding out how to 

 do this artificially, and thus succeeded in imitating every feature 

 of natural fertilization. Again a principle led him to the method 

 he tried — a principle which was doubtless faulty, though it had 

 its use, .and probably has been discarded and forgotten. We don't 

 know what it was. Sufficient it is that it led him to the truth. 

 He found that if, before treating the sea-urchin's egg with con- 



