ACTIVATION OF UNFERTILIZED STARFISH EGGS. 30 1 



It is to be assumed that the activation-process— as the earUest 

 step in development, an essentially constructive process— in- 

 volves syntheses of some kind. Now the intracellular as well as 

 other organic syntheses consist as a rule, in the union of two or 

 more molecules, with loss of water, to form larger molecules,— as 

 in the formation of fats from glycerol and acids, of starch and 

 glycogen from sugar, of polypeptides and proteins from amino- 

 acids, etc. In order to account for the readiness with which 

 these condensations occur in cells, it seems necessary to assume 

 that the protoplasm is the seat of energetic dehydrations, prob- 

 ably in certain localized situations (possibly at membranes or 

 other adsorption-surfaces). The artificial enzymatic synthesis 

 of triolein from glycerol and oleic acid has been found to take 

 place readily only when water is removed as completely as 

 possible from the reacting mixture.^ Hence the synthesis of 

 fats by enzyme action in cells is intelligible only on the assump- 

 tion that in the region of their formation there is energetic 

 abstraction of water or dehydrolysis. Certain biological facts 

 indicate that partial removal of water from cells is favorable to 

 syntheses of the above kind. According to Overton, plasmolysis 

 of plant-cells furthers the formation of starch in chloroplasts.^ 

 Butkewitsch also finds that the formation of starch in the 

 amylase-rich cortex of certain plants {Sophora, Rohinia) is 

 promoted by placing in strong sugar-solutions (10-20 per cent, 

 dextrose and saccharose) .^ The observations of Pavy and 

 Bywaters and of Rubner on the formation of glycogen by yeast 

 cells in strong sugar solutions constitute probably a further 

 instance of the same phenomenon.^ In general loss of water will 



1 Cf. the papers of Pottevin: Comptes rendus de V Academic, 1903, Vol. 136, 

 p. 1 1 52, and 1904, Vol. 138. p. 378; Taylor, Journal of Biological Chemistry, 1906, 

 Vol. 2, p. 87; Hamsik, Zeitschr.f. physiol. Chemie, 1909. Vol. 59. p. i ; Armstrong and 

 Gosney, Proceedings Roy. Soc, Ser. B, 1914, Vol. 88, p. 176. 



2 Overton, Vierteljahrsschrift d. naturf. Ges. in Ziirich, 1899, Vol. 44. pp. 131-2. 



3 Butkewitsch, Biochem. Zeitschr., 1908, Vol. 10, p. 314; cf. pp. 336 seq. 



4 Pavy and Bywaters, Journal of Physiology, 1907. Vol. 36, p. I49; Rubner, 

 Archivfur Physiologic, Suppl. 1912, p. 252, and ibid.. Vol. for 1913, p. 244. 



Pavy and Bywaters found that in pure dextrose solutions the deposition of 

 glycogen in yeast cells increased rapidly with increase in the concentration of dex- 

 trose up to an optimum. In 2 per cent, solutions there was little effect; in 4 per 

 cent., 8 per cent., and 16 per cent, solutions there was a rapid progressive increase 

 in the quantity of glycogen laid down in the cells to a maximum of over 13 per cent. 



