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 

 Sfhmrechinus granulosis and Arhacia '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 Gies,* 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 Cremer ® was unable to bring about fertilisation by 

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

 Wolfgang 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 with the formation of water and 

 oxygen, and of oxidising guaiaconic apid 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 a.nd of a peroxidase in the extracts of 

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

 all, 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 



^ Pidri, " Un Nouveau Ferment soluble : I'Ovulase," Archivea de Zoologie 

 Experimentale et Generate, vol. xxix., 1899. 



^ Dubois, "Surla Spermase et I'Ovulase," Gomptes Rendus de la Socieie 

 de Biologie, vol. lil., 1900. 



' Winkler (H.), " Uber die Furchung unbefruchteter Eier unter der Ein- 

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

 schaft der Wissenschaften zu Gottingtn, Mathemat.-Phys. Klasae, 1900. 



* Gies, " Do Spermatozoa contain an Enzyme liaving 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 Gesohlechtszellen von Amphibien und liber die BoUe dieser 

 Fermente bei den Vorgangeu der Entwicklungserregung," Biochemische 

 Zdtschrift, vol. vi., 1907. 



