CHAPTER 12 



CONCLUSION 



In my Preface I expressed a hope that this book would provoke 

 further experiments. The question is, what experiments? Pro- 

 phecies are always dangerous and usually wrong ; but for what it is 

 worth, I believe that the following subjects would repay further 

 investigation : 



(i) Morphology of pronuclear movements. 



(2) Sub-microscopic morphology of spermatozoa in sea water 

 and egg water. 



(3) Physiology of frog's egg jelly. 



(4) Turning mechanisms in plant spermatozoa. 



(5) Structure-action relationships in the chemotaxis of plant 

 spermatozoa. 



(6) Variations in the receptivity of different parts of the egg 

 surface. 



(7) Oxidative carbohydrate breakdown in eggs. 



(8) DNA content of eggs, spermatozoa and pronuclei. 



(9) Partial fertilization, using 'cylindrical' eggs. 



(10) Irritability of the zona pellucida. 



(11) K and Na fluxes across egg surface before and after 

 activation. 



(12) Conduction velocity of capacitance change at fertiliza- 

 tion. 



(13) Membrane resistance before and after activation. This 

 may be linked with (11). 



(14) EflFects of periodate and trypsin on heterologous fertiliza- 

 tion. 



(15) The morphology, physiology and biochemistry of fer- 

 tilization and parthenogenetic activation in any eggs other 

 than those of echinoderms. Japanese biologists have realised 

 the importance of this subject and in their hands it is beginning 

 to pay dividends. Novikoff's experiments, on the escape of 



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