32 NATURAL SCIENCE. July, 



As we have already said, a great result of the " Challenger " 

 Expedition, was the disproving of the existence of living fossils in the 

 recesses of the ocean. The inhabitants of the ocean-floor are strange 

 enough, but their strangeness is that of novelty rather than of 

 antiquity. The great depths of the ocean are poor in species and in 

 genera, and the species and genera are often allied to existing 

 littoral or pelagic forms. As Moseley was among the first to point 

 out, migration to ocean depths is a migration to an abnormal environ- 

 ment and could have come about only slowly. Perhaps the great 

 ocean depths were the last parts of the surface of the earth to be 

 populated, and their inhabitants have reached them slowly from 

 surrounding regions. The barriers to downward migration are 

 numerous. First there is the scarcity of food, due to the absence of 

 vegetable life. Next there is the absence, partial or complete, of 

 light. Again, downward currents must be excessively slow and rare, 

 so that there would be little chance of any but Benthos reaching 

 the greater depths. Lastly there is the enormous barrier of the 

 increasing pressure of the water, as the downward migration pro- 

 gresses. If the "Challenger" Expedition failed to find the living 

 fossils zoologists hoped for, it found a still more extraordinary aspect 

 of the kaleidoscope of life. 



P. Chalmers Mitchell. 



FORAMINIFERA. 



No less than Si/j. pages and 115 quarto plates were devoted to 

 the Foraminifera collected by the " Challenger." The monograph 

 was the work of Dr. H. B. Brady, whose ripe knowledge had been 

 early trained to a due regard for the simplification of nomenclature 

 by his collaboration and friendship with Parker and Rupert Jones. 

 The Report on the Foraminifera will always remain the great book of 

 reference on all the recent forms of this group ; it contained the basis 

 of a bibliography and of an index to known forms, and paved the way 

 for a surer and more definite classification. Perhaps the most 

 valuable and at the same time the newest of Brady's work was the 

 careful study and description of the previously little-known are- 

 naceous forms, some ten genera and numerous " species " being 

 described practically for the first time. The exact locality and depth 

 of the gatherings rendered it possible to compare the geographical 

 distribution of the Foraminifera. Brady was thus enabled to give de- 

 tailed lists of those forms which form the mass of the Globigerina ooze 

 (PI. iii. Fig. 4), those which form the red clay, those of shallow water, 

 and those of pelagic habits ; lists of the greatest value to workers in the 

 geological history of the group. He gave a detailed survey of the 

 works of previous authors on the subject, compared the various 

 classifications, and proposed his own view, redescribing every genus 

 and carefully confining it more exactly than hitherto, thus smoothing 

 the way for future workers to a remarkable degree. The elaborate 



