x l THE VOYAGE OF II.M.S. CHALLENGER. 



Forbes believed with all the intensity of the old school of naturalists in the immuta- 

 bility of species, and in specific centres of distribution ; he based his beliefs on facts of 

 his own observation, and if these now appear insufficient and unsatisfactory, it must 

 be remembered that he worked before Darwin's Origin of Species gave to naturalists the 

 modern ideas of natural selection and evolution. 



Forbes' name is inseparably associated with the bathymetrical distribution of marine 

 life, and his clearly defined zones — the Littoral, Laminarian, Coralline, and the Region 

 of the Deep-sea Corals — enormously facilitated the work of descriptive naturalists. 

 The region of deep-sea corals extended from 50 fathoms to an unknown depth, and 

 Forbes points out that vegetable life is entirely absent from it, and " as we descend 

 deeper and deeper in this region, the inhabitants become more and more modified, 

 and fewer and fewer, indicating our approach towards an abyss where life is either 

 extinguished, or exhibits but a few sparks to mark its lingering presence. Its confines 

 are yet undetermined, and it is in the exploration of this vast deep-sea region that 

 the finest field for submarine discovery yet remains." ' In another place he indicates 

 the plateau between Shetland and the Fseroe Islands, on which the depth nowhere exceeds 

 700 fathoms, as the place on which dredging is most likely to settle the cpiestion of the 

 existence of a zero of life, and he points out that while the life-zero is probably about 

 the 300 fathom line in the Mediterranean,, the researches of Arctic voyagers have shown 

 it to be much deeper in Polar regions. The disciples of all great men tend to assert 

 dogmatically what their master suggested hypothetically, and it was so with the 

 followers of Edward Forbes. They viewed the life-zero, not as a probability, but as a 

 certainty, building their belief more on the d priori absurdity of creatures being able to 

 live in the absence 'of light and air, and under the great pressure which must prevail 

 in the depths of the sea, than on any direct evidence. 



The United States Government sent out their first purely scientific expedition in 1838 

 under the command of Captain Wilkes. This expedition returned in 1842 ; its work was 

 chiefly geographical and astronomical, but during the first year a few dredgings were made 

 in shallow water, and a number of deep soundings were obtained at intervals during the 

 voyage. The sounding line employed was a copper wire, a great improve menton previous 

 methods. The great American naturalist Dana, who accompanied this expedition, added 

 much to the knowledge of several groups of shallow water and pelagic animals. 



A British Antarctic Expedition under Sir James Clark Ross sailed in the " Erebus " 

 and "Terror" in 1839, and returned safely in 1843. Like Sir John Ross in the, Arctic 

 voyages, his nephew was determined to make the most of his opportunities in all direc- 

 tions, and was seconded in his efforts by the able co-operation of Sir Joseph Dalton 

 Hooker, who accomjianied the expedition as assistant surgeon. Without neglecting 



1 Natural History of European Seas, p. 26, 1859. This classification was given as early as 1839. See Memoir of 

 Edward Forbes, p. 255. 



