636 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



constantly bring- the provision transports into the deep sea (15, pp. 49, 

 57). Thither, in addition, come the immense quantities of marine plant 

 and animal corpses, which daily sink into the depths and are borne 

 away by currents. Thither comes the constant "rain" of the corpses 

 of zonary Protozoa (especially Glohigerina and RafUoIaria), which 

 uninterruptedly pour down through all the zones of depth into the 

 deepest abysses, and whose shells form the most abundant sediment of 

 the deep sea, the calcareous Glohigerina ooze and the siliceous Radiolaria 

 ooze. In general, it seems to me that the daily supply of food materials 

 which the decaying corpses of numberless marine organisms furnish to 

 the others, is much more important than is commonly supposed.* How 

 much food would a single dead whale alone furnish? 



But especially important and not sufficiently valued in this regard 

 it seems to me, is the trophic importance of the benthos for the plankton. 

 Immense quantities of littoral benthos are daily carried out into the 

 ocean by the currents. Here they soon disappear, since they serve as 

 food for the organisms of the phmkton. If one weighs all these com- 

 plicated reciprocal relations, he obtains without counting- a sufficient 

 general conception of the "cycle of the organic material in the marine 

 world." 



COMPARATIVE AND EXACT METHODS. 



The farther the two great branches of biology, namely, morphology 

 and physiology, have developed into higher planes during the last 

 decade, so much tiirther have the methods of investigation in both 

 sciences diverged from one anothei-. In morphology the high worth of 

 comparative or declarant methods has always been justly more recog- 

 nized, since the general phenomena of structure {e. g., in ontogeny and 

 system ization) have been in great part removed from exact investi- 

 gation, and comprise historical problems, the solution of which we can 

 strive for only indirectly (by way of comparative anatomy and phylo- 

 genetic speculation). In physiology, on the -other hand, we constantly 

 strive to employ the exact or mathematical methods, Avhich have the 

 advantage of relative accuracy and which enable us to trace back the 

 general phenomena, of vital activity directly to physical (particularly 

 to chemical) processes. Plainly it must be the endeavor of all sciences 

 (of morphology also) to find and retain as much as possible this exact 

 mode of investigation. But it is to be regretted that among most 

 branches of science (and particularly the biological ones) thisls not 

 possible, because the empirical foundations are much too incomplete and 



*Heu8en values this source of food very slightly, because "only a very few aui- 

 malslive upon dead matter," and explains it iu this way, "that material in a state 

 of foul putrefaction requires a stronger digestive power than the organization of the 

 lower animals can produce " (9, p. 2). I must contradict both ideas. The sponges live 

 chiefly upon decaying organisms, as do also many Protozoa, Helminths, Crustacea, etc. 



