iv University of Calif ornia Publications in Zoology [Vol. 15 



plants to a life in the sea rather than to a life on land or in fresh 

 water? How and why did siieh structural adaptations arise? What 

 is it in structure that prevents marine animals and plants from living 

 on land or in fresh water? Again, the fundamental problems of 

 physiology, regarded as a branch of marine biology, is to determine 

 the niceties in function which adapt marine organisms to a marine 

 life, and to determine how and why such functional adaptations arose. 

 Similarlj% the central embryologieal problem concerned in marine 

 biology is to determine what structural and functional adaptations 

 are involved during successive stages in the life-histories of marine 

 animals and plants, and to determine how and why these adaptations 

 vary. Finally, the purpose of ecology, as a branch of marine biology, 

 is to determine how marine animals and plants are related to every 

 element of their environments, and to determine how they behave so 

 as to maintain these relations. 



Yet the belief in many quarters is that, unless the marine biologist 

 devotes his energies toward proving or disproving some evolutional or 

 other widely promulgated theory, his research is devoid of scientific 

 merit. Only last summer a prominent biologist plied me with these 

 questions : What is your study of the relation between chaetognaths 

 and their environments contributing toward an understanding of 

 evolution? What light is it throwing upon the hereditary process? 

 It was clearly implied that, if I could not foresee how it would bear 

 on some dominant theory, my research was superficial and unim- 

 portant. But does an animal do nothing important except evolve? 

 Does the meaning and significance of life consist solely in the process 

 by which one individual develops from another? Is it .superficial and 

 unimportant to measure the relations between organisms and their 

 environments when life is wholly dependent upon maintaining these 

 relations.' 



The marine biologist is not committed to investigating any phase of 

 evolution or heredity except as it concerns the evolution and heredity 

 of marine organisms, but he is committed, primarily, to finding out 

 what marine organisms are — as such. Incidentally, of course, he will 

 contribute toward a better understanding of the laws of evolution, 

 heredity, variation, and so on, and he will aid in solving many morpho- 

 logical, embryologieal. and other problems ; but only as by-products 

 of his primary obligation — to understand marine organisms. 



Broadly interpreted, this conception of marine organisms is that 

 the significance of no phenomenon essential to the life of any marine 



