A QUALITATIVE ANALYSIS OF THE EGG-SECRETIONS 

 AND EXTRACTS OF ARBACIA AND ASTERIAS. 



OTTO GLASER. 



(From the Marine Biological Laboratory at Woods Hole and the Zoological 

 Laboratory of the University of Michigan.) 



INTRODUCTION. 



Although it must have been seen earlier, F. R. Lillie ('12) was 

 the first, so far as I know, to throw emphasis on the observation 

 that when unfertilized Arbacia eggs are allowed to stand in a 

 small quantity of sea water, the supernatant liquid takes on a 

 reddish-brown color. The amount of discoloration varies 

 directly as the number of eggs present, the amount of sea water 

 used, and within limits, the time of exposure. If the eggs are 

 now precipitated with the centrifuge, and the fluid above is 

 decanted and filtered through paper, or simply decanted without 

 filtration, it can be very easily shown that substances are present 

 which do not occur in ordinary sea water. 



I. ANALYSIS BY MEANS OF SPERM-SUSPENSIONS. 



The best method of analysis is that discovered by F. R. Lillie, 

 and although it was not my primary purpose, I have verified a 

 number of his results ('I2 1 , 'I3 1 , 'i3 2 ). Following Lillie, I shall 

 present my material under four heads: (.4) Activation; (B) 

 Chemotaxis; (C) Agglutination; (D) Paralysis. 



A. ACTIVATION. 



i. I so- Activation. As Lillie has pointed out, the phenomena 

 of activation are presented with unequal clearness in different 

 forms. The spermatozoa of Nereis for instance are so active in 

 sea water that the effect of the egg-secretion is obscured. With 

 Arbacia, the sperm, as is well known, are also active in sea-water, 

 nevertheless a noticeable increase in the rate of their movements 

 can be observed after the addition of a drop of the egg-secretion. 

 Asterias forbesii is really much more favorable than either Nereis 

 or Arbacia for the detection of the activating effect, for here the 



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