58 



environment, julged by the variety of animal forins that have develoo- 

 ed in it, than the other natural brines of very different character, 

 such as the salt lakes, that also support life? Or 5oes this merely 

 reflect a colonization of the latter by protoplasm, the character- 

 istic properties of which reflect a marine or terrestrial origin? 

 The study of such brines should, by thriir abnormality, enlie-hten us 

 as to the oceanic environment. 



All of this converges in turn upon the basic riddle (of the 

 real answer to which we have not yet gained f::ven an inkling) of the 

 basis for the group and specific differences in protoplasm: differ- 

 ences that are reflected in all the diversity of life that has 

 existed on our plant t. 



3. Marine Bacteriology 



Pres<^nt-day femiliprity with medical science makes us 

 prone to think first of Bacteriology in its relation to human 

 diseases. The problem of disease, however, seems not to be of great 

 moment in the sea. Thus, while fishes (and no doubt other marine 

 animals) do suffer from a variety of bacterial inflections, and while 

 the hutnan aspects of oacteriology do r-ach into the sea to some 

 extent, when typhoid - and other disease-bacteria, coming from the 

 land, gain foot-hold in the bodit-s of oysters, clams, and other 

 shell-fish, most of the pathogenic bacteria (though capable of liv- 

 ing and multiplying in sea water, with added nutrients) have been 

 found to succumb rapidly in normal sea water. By and larre, the 

 disease-bacteria of man nd of the higher animals do not thrive in 

 the open sea. 



The proDlams of Karine Bacteriology th?t we wish to emphasize 

 here are more akin to those of soil bacteriology; they center around 

 the role that bacteria play in keeping in motion the cvcle of matter 

 through its organic and inorganic stages in the sea. 



If we write less confidently on this subject that we have on 

 Oceanic Biology (pa?e 43). or on Marine Physiology (^ase 50 ), it 

 is because our knowledge of bacteria in the sea is still scant. 

 But such glimpses as we have gained of their activities there are 

 enough to show that these must be assayed before we can hop^ to under- 

 stand the maintenance of organic fertility in the oceans. 



The simplest task of Marine Eacterioloj?:y is perhaps to trace the 

 airecu service these lowly organisms render 'to the higher, in orovid- 

 ing_ the latter with proteid food. That protozoans do'feed on bacter- 

 ia in the sea is established. In fact, recent studies su?g-st that 

 m this passive way the bacteria that thrive on the organic detritus 

 that accumulates in shoal waters, and the protozoa that prev upon the 

 bacteria are essential links in the food chain of coastal waters, 

 where the molluscs and other animals that feed on detritus gain their 

 nourishment, less from the food stuffs therein contained, than from 

 the bacteria and protozoa eaten at the same time. 



This question is a Quantitative one; the answer depends on th-^ 

 numerical distrioution of bacteria regionally and with d-p+h In 

 general, the sea water is much richer in bacteria near shore, where 

 land drainage maintains a state m.ore fertile for them, than out in 

 the open ocean; especially is this true of the forms that subsist on 

 the excreta of animals. But viable bacteria are also known to exist 



