FOREWORD 



This is the first symposium in the field 

 of the biological sciences to be published 

 for the American Association for the Ad- 

 vancement of Science. But there have been 

 several in the related field of medicine and 

 public health — The Cancer Problem, Tuber- 

 culosis and Leprosy, Syphilis, and Mental 

 Health — and two in the field of chemistry — 

 Applications of Surface Chemistry in Biol- 

 ogy and Recent Advances in Chemical Phys- 

 ics. The symposia that have been published 

 are, however, only a fraction of the broad 

 surveys and integrations of science, often 

 ranging far across the boundaries that sepa- 

 rate its usual divisions, which have been 

 organized and presented at the meetings of 

 the Association. 



Plans for this symposium on The Migra- 

 tion and Conservation of Salmon, like those 

 for each of the earlier symposia, were de- 

 veloped by distinguished specialists. All 

 the participants in the symposium were in- 

 vited and their contributions together con- 

 stitute a comprehensive, integrated and 

 annotated digest of what is known about an 

 important and interesting subject. Since 

 salmon are found in the waters of the 

 United States, Canada and Great Britain, 

 one or more specialists from each of these 

 countries contributed to the symposium. 



On the day following the presentation of 

 the symposium, the participants in it and 

 others met in two half -day sessions for free 

 and informal discussions and criticisms of 

 the formal papers. Fortunately these in- 

 formal discussions were reported steno- 

 graphically, for they proved to be so valu- 

 able that, as edited by Dr. A. G. Huntsman, 

 they are included in this volume. 



In the problem of accounting for the 

 migration of salmon one enters a field in 

 which science and romance appear to meet. 

 At least it has often been maintained that 

 the mature fish, moved by some strange 

 super-human instinct, return after several 

 years at sea to precisely the stream of their 

 birth and there, in their first home, deposit 

 and fertilize their eggs, to begin a new gen- 

 eration. The method of science, however, 

 is to look for explanations of phenomena in 

 the general properties of the world about 

 us, even though at first this seems to us 

 almost or quite supernatural. During the 

 past two or three decades these methods 

 have been extensively used in attempts to 

 account for the migrations of salmon. Not 

 only have the currents and the temperatures 

 and the chemical constitutions of the waters 

 in which they live been extensively sur- 

 veyed, but salmon of various ages in num- 

 bers running into tens of thousands have 

 been tagged and hundreds of thousands 

 have been marked. In spite of the fact that 

 large numbers of these tagged or marked 

 salmon have been recovered, as reported in 

 detail in this symposium, the story of what 

 takes place in their migrations is yet far 

 from being complete, and the explanations 

 of them are as much open to question. It 

 is for these very reasons that this volume is 

 timely and valuable from the scientific point 

 of view. And it will likewise be of interest 

 not only to those who fish and hunt because 

 of the spirit of the chase that still lives in 

 us, but also to the countless numbers who 

 feel a dim and ill-defined kinship with all 

 living things on the earth. 



F. R. MOULTON 



L I B R A R 



