300 THE PHYSIOLOGY OF REPRODUCTION 



to the action of ferments present in the spermatozoon. Pi^ri ^ 

 claimed to have extracted from the spermatozoa of Stron- 

 gylocentrotus lividus and Echinus esculentus a ferment, "ovulase," 

 which induced segmentation of mature ova. Similar observa- 

 tions were made by Dubois ^ on Echinus, and by Winkler ' on 

 Sphwrechinu^ granulosis and Arbacia pustulosa. The evidence 

 on which these authors base their conclusion is, however, not 

 very convincing, and the searching criticism to which their 

 observations were subjected by Gries,* who repeated their ex- 

 periments, tends to show that their results were due to other 

 factors. Gies was unable to extract either from spermatozoa 

 or from fertihsed ova any enzyme or zymogen capable of 

 causing development in mature ova of the same species. 

 Similarly Gremer ^ was unable to bring about fertilisation by 

 means of the press-juice obtained from spermatozoa (see p. 222). 

 WoKgang Ostwald® has determined the amounts of oxidising 

 ferments present in the ovaries and testes of toads, frogs, and 

 newts. The watery extracts of these organs had the power of 

 decomposing hydrogen peroxide Avith the formation of water and 

 oxygen, and of oxidising guaiaconic acid to guaiacum blue, so 

 that a blue colour appeared when these extracts were added to 

 an emulsion of guaiac resin. These reactions indicate the 

 presence of a catalase and of a peroxidase in the extracts of 

 the sexual glands. Such ferments are present in many, if not 

 aU, organs and tissue fluids, but a special significance is attri- 

 buted by Ostwald to their presence in the ova and spermatozoa, 

 because he found the spermatozoa to contain more catalase 

 and more peroxidase than the ova, and because the activity 



' Pi^ri, " Un Nouveau Ferment soluble: I'Ovulase," Archives de Zoologie 

 Experimentale et Generale, vol. xxix., 1899. 



' Dubois, " Sur la Spermase et I'Ovulase," Gomptes Bendus de la Societe 

 de Biologic, vol. lii., 1900. 



' Winkler (H.), "tjber die Furohung unbefruchteter Eier unter der Ein- 

 wirkung von Extraktiostoffen a. d. Spermata," Nachrichten der kgl. Gesell- 

 schaft der Wissensckaften zu Gottingin, Mathemat.-Phys. Klasse, 1900. 



■* Gies, " Do Spermatozoa contain an Enzyme having the Power of Causing 

 Development of Mature Ova ? " American Journal of Physiology, vol. vi., 1901. 



^ Quoted from Loeb, Dynamics of Living Matter. 



* Wolfgang Ostwald, "Uber das Vorkommen von oxydativen Fermenten 

 in den reifen GeschlechtszeUen von Amphibien und uber die RoUe dieser 

 Fermente bei den Vorgangen der Entwicklungserregung," Biochemische 

 Zeitschrift, vol. vi., 1907. 



