PROGRESS IN BIOLOGICAL INQUIRIES 39 



fairly closely circumscribed part of ecology which deals primarily 

 with the factors, both inherent and environmental, affecting the 

 abundance of individuals of a given species. 



Properly considered, these studies are as purel}^ scientific and bear 

 as directly upon the larger problems of biology as do other biologi- 

 cal sciences, even including genetics. Is it not as important to know 

 how a species is maintained as to laioAv how it arises? Is it not as 

 important to know how a species is adjusted to its environment and 

 how it responds and adapts itself to changes in its environment as 

 to know these same things for the individual? The adaptive proc- 

 esses in the individual are, of course, bound up with the adaptation 

 of the species and the survival of the individual with the survival 

 of the species. The two are inevitably closely associated, but there 

 is something more involved in the survival of a species than in the 

 survival of an individual. This maj^ seem paradoxical but it is 

 obviously true, since species are maintained over long periods of 

 time, whereas the individuals composing the species are continually 

 changing — new individuals coming in, existing for a relatively short 

 period of time, and then dying. In a sense, the species is an in- 

 dividual and has an existence of its own, a growth and survival of 

 its own quite apart from the existence, growth, and survival of the 

 individuals which at any time may compose it. It has periods of 

 stress when its survival is precarious and which may end in its 

 extermination. Naturally the same factors which result in the ex- 

 termination of a species result in the death of the individuals com- 

 posing the species, but it is with the larger aspects of the problems 

 of adaptation and survival, those dealing with the species as a unit, 

 that life-history studies are concerned. 



The condition of a species, whether young and growing healthily, 

 old and characterized by senility, well or poorly adapted to its 

 environment, may be measured by the abundance of individuals; and 

 in any given form the fluctuations in abundance are indicative of the 

 success or failure of the species as a whole to adapt itself to the 

 various changes in its environment. From this point of view life- 

 history studies, which in the end are primarily concerned with dis- 

 covering the causes of fluctuations in abundance, can be fully jus- 

 tified as essays in pure science and have a distinct place in the 

 biological sciences quite apart from any economic use to which the 

 resultant information may be put. It happens, however, that it is 

 exactly this sort of information that is essential to the scientific 

 conservation and development of biological resources: — in this in- 

 stance our aquatic resources. 



The foregoing is not to be interpreted as in any sense an apology 

 for the prominent place taken by life-history studies in the work of 

 the division. It is, rather, an explanation of the nature of the inves- 

 tigations and of the attitude of those directly concerned — an expla- 

 nation for the benefit of those scientists who incline to the view that 

 no investigation undertaken primarily for economic reasons can pos- 

 sibly be of scientific value. 



The following pages contain brief accounts of tlie accomplish- 

 ments in the various researches during the half year July 1 to 

 December 31, 1924. In general, the accounts as given were prepared 

 by the investigators in direct charge. 



