METHODOLOGY OF NATURAL SCIENCE. 93 



and chemistry must use the discoveries and methods of the natural 

 history sciences in order to round themselves out. But physics, under 

 such general designations as geo-physics and celestial physics, seems 

 now to be moving rapidly toward a clear perception of its proper re- 

 lation to, and dependence upon, the natural history sciences. The 

 notable recent achievements in terrestrial magnetism, geodesy, meteo- 

 rology, oceanography, and stellar distribution and growth, may be 

 specially noted in illustration of this movement. 



Although chemistry is considerably behind physics in discovering 

 its interdependence with natural history, astronomical spectroscopy, 

 taxonomic bio-chemistry, and especially the discoveries in radio 

 activity, in so far as these are revealing the evolutional changes and 

 phyletic affinities of chemical substances, are highly suggestive as 

 to what the future may have in store for chemistry. It seems that 

 chemistry has reached a stage in which it recognizes itself as no longer 

 justified in assuming, on the basis of any evidence it possesses, " that 

 the elements of to-day were eons ago the same substances and pre- 

 served their properties unaltered." ^ This by itself is an important 

 step toward converting chemistry into a genuinely historical science. 



Now comes the kernel of this communication. The drawing into 

 more vital mutual dependence of the two groups of science, the exact 

 sciences, formerly so-characterized, and the natural or descriptive 

 sciences, formerly so-called,^ might be expected to enrich both groups. 



For that is exactly what all natural drawing together does. And 

 expectation is being realized. The paper on method here presented 

 has grown out of the joint labors of a mathematical physicist working 

 at oceanography as a branch of geo-physics, and a systematic zoologist 

 working at the distribution of animals as an aspect of the broader 

 problem of the relation of organisms to their natural environments, 

 the two investigators having been brought together in the enterprise 

 of gaining as much knowledge as possible of the pelagic life of a 

 particular, restricted area of the Pacific Ocean. 



Specifically the problem is: Given the requisite taxonomic knowl- 

 edge of a natural group (an order, say, with its several genera and 

 species) of pelagic animals, and the requisite facts as to the vertical 

 distribution of these animals through diurnal and annual cycles; 



1 "Old Age" of Chemical Elements, by Ingo W. D. Hackh, Science, April 4, 

 1919, p. 328. 



2 As though a flock of seven wild geese were not physical and the counting 

 of them were not exact; and as though a discharge of electricity between 

 clouds were not natural and could not be or did not need to be, described. 



