GENERAL CHEMISTRY OF LIFE PHENOMENA 17 



tion in the yeast cell, the zymase ; * but we are here chiefly concerned 

 with the fact which nobody has failed to confirm, that the presence of 

 oxygen favors cell division and growth in yeast cells; that without 

 oxygen these processes soon come to a standstill. The same is true 

 for animals. I made a large number of experiments on the effects of 

 lack of oxygen on the newly fertihzed eggs of sea urchins and fishes 

 (Fundulus and Ctenolabrus).t The eggs were kept in small Engel- 

 mann gas chambers through which a current of hydrogen was sent to 

 drive out the oxygen and the COj formed by the eggs. In the eggs of 

 sea urchins and Ctenolabrus, the segmentation stopped in less than an 

 hour after the beginning of the current of hydrogen. When the air was 

 again admitted, the eggs began to divide, provided they had not remained 

 too long without oxygen. The eggs of Fundulus, also a marine fish, 

 do not respond as quickly, inasmuch as it required about twelve hours 

 before they stopped segmenting in the current of hydrogen. Similar 

 results were obtained by Godlewski % on the eggs of frogs. As far as 

 growth and regeneration are concerned, I have found that without 

 oxygen both are impossible in Hydroids (Tubularia).§ In plants, 

 conditions are the same; seeds require a comparatively abundant 

 supply of oxygen for germination. || The question arises, as to what 

 connection exists between the oxidations in hving tissues, and cell divi- 

 sion and growth. We cannot answer this question as we do not know 

 into which form of energy chemical energy must be transformed in 

 order to produce cell division and growth. But another point may 

 be settled. For the process of growth an increase in the quantity of 

 living matter is required, and this requires synthetical processes. 

 Schmiedeberg has called attention to the fact that oxygen is especially 

 fitted to serve as a connecting hnk between organic radicals, and that 

 through the intervention of oxygen a great many syntheses in the 

 body may occur. He. mentions, as an example, the combination in 

 which sulphuric acid may appear in the urine. When a dog is fed with 

 benzol, the benzol appears in the urine as benzolsulphate, provided 

 that enough free oxygen is present. According to Schmiedeberg, 

 this synthesis occurs in the following way : — 



2 SO,Q^ + 2 QHe + O, = 2 SO -Q^^jj + 2 H O. 



* H. Buchner denies that lack of oxygen increases the rate of alcoholic fermentation by 

 yeast, although the facts seem to speak in favor of Pasteur's statement. E. Buchner, H. 

 Buchner, und M. Hahn, Die Zymasegarung, Munchen und Berlin, 1903. 



t Loeb, Pfluger's Archiv, Vol. 62, p. 249, 1895. 



t Godlewski, Zeits.fUr Entwickelungsmechanik, Vol. II, p. 585, 1901. 



§ Loeb, Untersuchungenzurphysiologischen Morphologic der Tiere, II, Wiirzburg, 1 89 1. 



II M. Traube, Gesammelte Abhandlungen, p. 148. 



