CLUSTER FORMATION OF SPERMATOZOA CAUSED 

 BY SPECIFIC SUBSTANCES FROM EGGS 



JACQUES LOEB 



From the Laboratories of the Rockefeller Institute for Medical Research, New York 



INTRODUCTION 



In several papers F. Lillie^ has described a very interesting 

 specific phenomenon of apparent sperm agglutination which oc- 

 curs when the sperm is mixed with sea water which has been in 

 contact for a short time with a sufficient quantity of eggs of the 

 same species (Arbacia and Nereis) : 



In the case of Arbacia the addition of two or three drops of egg-sea 

 water | (i.e., one volume of eggs to four volumes of sea water) which has 

 stood half an hour, to about 2 cc. of fresh milky sperm suspension causes 

 formation of agglutinations 1 to 2 mm. in diameter in a few seconds. 

 The agglutination may be so strong that the fluid between the white 

 agglutinated masses appears perfectly clear. The masses gradually 

 fade from view in a few minutes, but microscopic agglutinations may 

 remain half an hour or more. 



The agglutination is, therefore, only transitory or reversible, 

 as Lillie states. It is specific since e.g., the supernatant sea water 

 of Arbacia eggs acts only on Arbacia sperm and not on other 

 sperm. 



It is very natural that Lillie should have been led to the idea 

 that such a striking specific phenomenon as this agglutination 

 must play a role in the process of fertilization and he has recently 

 offered a very carefully worked out hypothesis which makes this 

 phenomenon of agglutination not only the center of the process 

 of fertilization and of artificial parthenogene'sis but he even hints 

 that it may be involved in the phenomena of heredity. 



1 Science, N.S., vol. 36, p. 527, 1912; Journ. Exper. ZooL, vol. 14, p. 515, 1913. 



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