XIX 



THE FERTILIZING EFFECT OF SPERM EXTRACT 



1. In 1899 Fieri published a note to the effect that by merely 

 shaking up the testes of the sea-urchin in sea-water he had 

 been able to extract a substance which fertilized the egg of the 

 sea-urchin. 1 The sea- water containing the spermatozoa was 

 filtered after the shaking, and the filtrate added to the eggs. 

 The eggs developed. As the author himself states, and as is 

 generally known, spermatozoa pass through filter paper, and 

 so one cannot quite understand on what the author bases his 

 statement that we are concerned here with a fertilization by 

 sperm extract, and not by living spermatozoa; control experi- 

 ments were not performed. A better addition to the solution 

 of the problem was made by Winkler. 2 He states that his 

 work has not gone beyond a preliminary stage. His experi- 

 ments consisted in putting the spermatozoa of two kinds of 

 Naples sea-urchins, Sphaerechinus and Arbacia, into distilled 

 water for half an hour. The filtrate was able to produce the 

 first segmentation stages in the sea-urchin. It will be seen, 

 however, that Winkler did not work with unaltered sea-water, 

 and it is possible that the alteration of the sea-water and not 

 the hypothetical substances extracted from the sperm was the 

 cause of the segmentation that he observed. 



If the spermatozoa were simply killed by being heated in sea- 

 water to between 50 and 60 C., and the eggs put in this liquid, 

 nothing happened. But if they were put into distilled water for half 



1 T. B. Fieri, " Un nouveau ferment soluble: L'ovulase," Arch, de Zool. exper. 

 et gen., XXIX, 1899. 



2 H. Winkler, " Ueber die Furchung unbefruchteter Eier unter der Einwirkung 

 von Extractivstoffen aus dem Sperma," Nachrichten der Ges. d. Wissensch. zu 

 Gottingen, 1900, 187. 



201 



