1896.] ■ Life Before Fossil*. 191 



Yet the oceanic waters to-day swarm with swimming life, 

 and in all probability did so then. This life, as now existing, 

 contains many high as well as numerous low forms. Then it 

 must have consisted of low forms only. The wealth of exist- 

 ing minor sea life, as observed by the unassisted eye and 

 revealed by the microscope, is simply boundless. Small jelly 

 fish are met with in vast armies, hundreds of miles in extent, 

 and descending to many feet in depth. Pteropods, both the 

 naked and the shelled forms, occur in prodigious multitudes. 

 The minute copepod crustaceans are found in countless 

 swarms, and, though consumed in myriads daily by herring 

 and other fish, by medusae, siphonophora and other inverte- 

 brates, and even by the whale, they are so productive that 

 their numbers seem undiminished, being found over .vast areas 

 of surface and extending through more than a mile in vertical 

 depth. Below these again are hosts of microscopic larva' and 

 minute animals, and still lower are countless swarms of proto- 

 zoa, such as radiolarians, globigerime, etc. 



Here, then, are innumerable swarms of swimming and float- 

 ing forms, in most part carnivorous, but necessarily requiring 

 a vegetable basis of nutriment, The foundation food supply for 

 such a mighty host must be enormous in quantity. The visi- 

 ble plant life of the ocean, the algse which grow on the bottom, 

 would not sustain a tithe of such an army. The microscope 

 must again be brought into requisition, and.this useful instru- 

 ment reveals to us an extraordinary profusion of unicellular 

 plants — diatoms, coccospheres, trichodesmiums, and a few other 

 types — which extend from the surface to the lowest level of 

 light penetration, and are so extraordinarily numerous and 

 prolific as to supply food for all the oceanic host. These, and 

 the protozoa which feed upon them, form the basic food sup- 

 ply for the countless myriads of living forms which compose 

 the fauna of modern seas. 



Yet, were the conditions of the ocean as they exist to-day to 

 be sought for by some far future geologic delver int^o the myste- 

 ries of the rocks, almost nothing of this profusion of life would 

 be revealed, discovery being nearly or entirely confined to 

 such forms as possess hard skeletons, internal or external, of 



