82 THE WONDER OF LIFE 



showed that most of the invertebrate types were represented 

 at depths of 600 fathoms or more. These preliminary 

 sampUngs led on to the famous voyage of the Challenger 

 (1872-76), which, like Darwin's voyage on the Beagle, 

 may be ranked as a Colmnbus voyage in the history of 

 biology. Darwin's voyage led to the discovery of a new 

 world — for the evolution idea made everything new ; the 

 Challenger voyage led practically to the discovery of the 

 new world of the Deep Sea. Under Wyi^ille Thomson's 

 leadership the explorers cruised for three and a half years 

 over the wide oceans, crossing the Atlantic five times, 

 covering 68,900 nautical miles, reaching down with the 

 long arm of the dredge to depths equal to reversed Hima- 

 layas, raising treasures of animal life from over five hundred 

 stations, and bringing home spoils which have taken forty 

 huge volumes to describe. The results, under Sir John 

 Murray's editorship, have suppUed a broad foundation 

 for the science of oceanography, and given a powerful and 

 lasting impulse to zoology in general. 



Without dwelhng on historical facts, we venture to call 

 attention to three points. (1) It was out of a practical 

 task that the stimulus to Deep-Sea exploration arose, 

 and there has been on the part of science some repayment 

 of this debt. (2) What happened is a warning against 

 dogmatism. It is not very long since an authority spoke 

 of the floor of the Deep Sea as ' an area regarding which 

 nothing was known, nor could be known ' ; and now there 

 is a large Hbrary of descriptive reports. (3) What the 

 Challenger began has been followed up by expeditions 

 from most of the countries of Europe and by the magnifi- 

 cent work of the late Professor Alexander Agassiz in 

 America. 



