BULLETIN OF THE UNITED STATES FISH COMMISSION. 2 Go 



exhaustive observations of the depths of the ocean all over the globe 

 would undoubtedly prove of immense interest to science. And what 

 nation was better fitted to take the matter in hand than England, which 

 proudly "rules the waves," and therefore, more than any other nation, 

 would derive benefit from a thorough knowledge of the ocean ? 



The English statesmen were fully aware of the vast importance of 

 this subject, and with the consent of Parliament they opened the door 

 of the treasury wide. A fine frigate of the Eoyal Navy, called the 

 Challenger, was selected for this expedition ; the guns were taken out, 

 and she was fitted out anew, with the special view of taking observa- 

 tions. The vessel was manned bj r picked officers and men, and a num- 

 ber of prominent naturalists became members of the expedition, at the 

 head of which was Mr. Wyville Thomson, who had had charge of the 

 first observations mentioned above. 



Toward the end of the year 1872 the Challenger departed on her 

 voyage around the world, cruising in all directions in the Atlantic and 

 Pacific. The expedition occupied three years, and on its return the 

 Challenger had sailed more than 20,000 miles. The observations had 

 been directed to different subjects : the temperature of the water from 

 the surface to the bottom ; the depth of the sea in various places ; the 

 nature of the bottom and the animals inhabiting it ; whether the 

 water was stationary or whether there were currents, the direction and 

 swiftness of these currents, &c. With the excellent instruments plum- 

 mets were hauled up from great depths, among them one of 8,363 

 meters. This was the greatest depth which was sounded, which of 

 course does not imply that there are no greater depths in the sea, for 

 it can hardly be expected that by chance the plummet would sink into 

 the greatest depth of the sea. 



And what do we learn, regarding this very interesting subject, from 

 the expedition of the Challenger. The naturalists made everywhere 

 the same observations which they had made in the first waters exam- 

 ined by them. Nowhere did they find a lack of living beings, and at 

 the bottom of the sea they found all kinds of invertebrates. They also 

 hauled up some fish which were evidently intended to live at the bot- 

 tom, and which could not live anywhere else. When the fish were 

 brought up their air bladders protruded from their mouths, and their 

 eyes protruded from their sockets; nothing but the great pressure ex- 

 isting in these depths is able to keep these organs in their places. 



From the depth crustaceans were brought up as well formed as those 

 of the surface waters, but they were either entirely blind or had no 

 eyes at all. " No wonder," people will say, " for these organs are en- 

 tirely useless in the dense darkness prevailing in these depths/' 

 Granted ; but what do those animals which have eyes, and which also 

 live in the depths, do with those organs ? Are we certaiu that there is 

 in these depths an entire absence of light ? A remarkable statement 

 made by the naturalists of the Challenger seems to make this matter 



