iv PREFACE 



sions, H. B. Steinbach, R. J. Flipse, and T. Hayashi, have been in- 

 cluded as contributions. An additional paper (R. Rikmenspoel) was 

 added as a result of highly appropriate comments from the floor. We 

 are indebted to Sir James Gray, unfortunately unable to attend, for 

 his willingness nevertheless to contribute an introductory chapter. 



The symposium, made possible by a generous grant from the U.S. 

 Public Health Service through the National Institutes of Health, was 

 held under the joint aegis of the American Association for the Ad- 

 vancement of Science and the American Society of Zoologists, and 

 cosponsored by the Society ol General Physiologists. To all who con- 

 tributed to the presentation and publication of this symposium sincere 

 gratitude is due. 



David W. Bishop 



