10 president's address. 



share the fate of Bathybius in the future? Some may, but even if they 

 do they may well have been useful steps in the progress of science. 

 Although like Bathybius they may not have fulfilled the promise of their 

 youth, yet, we may add, they will not have hved in the minds of man 

 in vain. 



Many of the phenomena we encounter in oceanographic investi- 

 gations are so complex, are or may be affected by so many diverse 

 factors, that it is difficult, if indeed possible, to be sure that we are 

 imravelling them aright and that we see the real causes of what we 

 observe. 



Some few things we know approximately — nothing completely. We 

 know that the greatest depths of the ocean, about six miles, are a 

 little greater than the highest mountains on land, and Sir John Murray 

 has calculated that if all the land were washed down into the sea the 

 whole globe would be covered by an ocean averaging about two miles in 

 depth. ^ We know the disti'ibution of temperatures and salinities over 

 a great part of the surface and a good deal of the bottom of the oceans, 

 and some of the more important oceanic currents have been charted 

 and their periodic variations, such as those of the Gulf Stream, are being 

 studied. We know a good deal about the organisms floating or 

 swimming in the surface waters (the epi-plankton), and also those 

 brought up by our dredges and trav/ls from the bottom in many parts 

 of the world — although every expedition still makes large additions 

 to knowledge. The region that is least known to us, both in its physical 

 conditions and also its inhabitants, is the vast zone of intermediate 

 waters lying between the upper few hundred fathoms and the bottom. 

 That is the region that Alexander Agassiz from his observations with 

 closing tow-nets on the Blake Expedition supposed to be destitute of 

 life, or at least, as modified by his later observations on the Albatross, 

 to be relatively destitute compared with the surface and the bottom, in 

 opposition to the contention of Murray and other oceanographers that 

 an abundant meso-plankton was present, and that certain groups of 

 animals, such as the Ohallengerida and some kinds of Medusae, were 

 characteristic of these deeper zones. I believe that, as sometimes 

 happens in scientific controversies, both sides were right up to a point, 

 and both could support their views upon observations from particular 

 regions of the ocean under certain circumstances. 



But much still remains unknown or only imperfectly known even 

 in matters that have long been studied and where practical applications 



^ It vfae possibly in such a former world-wide ocean of ionised water that 

 according to the recent speculations of A. H. Church (Thalassiofhyta, 1919) the 

 first living organisms were evolved to become later the floating unicellular 

 plants of the primitive plankton. 



