STUDIES OF FERTILIZATION. 



EXP. 9. TEMPERATURE 16.5 C. 



In a only 50 per cent, formed full membranes (under-exposure). 



In b 95 per cent, formed full membranes. 



In c 50 per cent, formed full membranes (over-exposure). 



In a shaking destroyed all memberane. 



In b shaking destroyed 50 per cent, of the membranes. 



In c shaking destroyed 20 per cent, of the membranes. 



LITERATURE. 



Loeb, J. 



'13 Artificial Parthenogenesis and Fertilization (p. 234). University of 

 Chicago Press, Chicago, 312 pp. 



'15 On the Nature of the Conditions which Determine or Prevent the En- 

 trance of the Spermatozoon into the Egg. American Naturalist, Vol. 

 49, PP. 257-285. 

 Just, E. E. 



'19 The Fertilization Reaction in Echinarachnius parma. III. The Nature 

 of the Activation of the Egg by Butyric Acid. BIOL. BULL., Vol. 36, 



PP. 39-53- 

 Moore, C. R. 



'16 On the Superposition of Fertilization on Parthenogenesis. BIOL. BULL., 

 Vol. 31- 



