Epilogue 



DAVID W. BISHOP 



Department of Embryology, Carnegie Institution of Washington, Baltimore, Maryland 



The degree of success of this symposium during which the fore- 

 going papers were presented is evident from the contributions them- 

 selves. As an assemblage of surveys of recent findings and reports of 

 new data, they indicate what has been accomplished and what Ave 

 would like to know — in short, where we stand. In an evaluation, 

 rather than a summary, of results of such a symposium, it behooves us 

 to recall that a symposium, while literally a "drinking party," is also 

 a "collection of opinions" on a given subject. The collection has been 

 varied and necessarily tentative. It is certainly not the last word, as is 

 painfully evident to one who completed, just prior to these meetings, 

 a review of the subject which is already, in some respects, obviously 

 obsolete (Bishop, 1962). Both current advances and certain major 

 unresolved questions have been brought sharply into focus. 



The reports from the University of Cambridge contribute sig- 

 nificantly, as usual, to the understanding of wave formation and the 

 nature of propulsion, while at the same time urging caution in in- 

 terpretation and formulating a plea for technical innovation and im- 

 proved observational methods. In the light of the closeness of fit of 

 observed and calculated data of such parameters of sperm motility 

 as velocity and power requirement, one accepts with tongue in cheek 

 their warnings against their own overspeculation! Lord Rothschild's 

 suggestion that calculations of biophysical data on a per sperm basis 

 be taken not too seriously has some merit since, as he points out, we 

 really do not know what the effect is of one sperm on an adjacent one. 

 Indeed, Rikmenspoel's findings are significant in that they demon- 

 strate an antagonistic repulsion of neighboring cells rather than a 

 degree of thermodynamic cooperation extrapolated from the deriva- 

 tions of Sir Geoffrey Taylor. Nevertheless, in dealing with a popula- 

 tion of cells, particularly one as clean and homogeneous as sperm 



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