THE NATURAL HISTORY OF THE SEA. 389 



Pelseneer, illustrated by Mr. Huxley's beautiful drawings, 

 and the Report on Oceanic Circulation, by Dr. Buchan, 

 with sixteen valuable maps. 



Since the return of the Challenger, marine exploration 

 has been carried on by the United States ships, Tuscarora, 

 Blake, Albatross, Gettysburg and Enterprise, the German 

 Gazelle, and the National or Plankton Expedition under 

 Hensen in the Atlantic, the Norwegian Vbringen, the 

 Prince of Monaco's Princesse Alice, the Italian Washing- 

 ton and Vet tor Pisani, our own Knioht Enfant, Triton, 

 etc., and by the Swedish Government in the Baltic and 

 North Sea. Last of all much is to be expected from the 

 work of the Frani. All the ships cited, and many others, 

 have been steadily gathering- facts ; but to the naturalist 

 perhaps none of them, since the Challenger, has gained 

 such a harvest of interesting" results, worthily published, as 

 Hensen s Plankton Expedition. It would be out of the 

 question to attempt more than notice of some of the 

 weightiest results recorded in the publications of the 

 voyage. Among those of general interest the researches 

 of Bernhard Fischer (3) and Franz Schiitt (4) claim 

 particular attention. 



xAmong the dark places in our knowledge of the economy 

 of the sea there have been until recently two in particular 

 urgently calling for more light. It has been a common- 

 place reflection of sea naturalists for many years (though 

 Dr. Fisher appears to think it an original idea of Hensen's) 

 that the minute free floating plant life of the sea must fur- 

 nish the pastures of the animal life of the sea. The crucial 

 observations, to be noticed presently made by Professor Mc- 

 intosh and Mr. George Murray {7) settle by proof the actual 

 fact of the diatoms affording sustenance to the animals of 

 the sea — a fact long foreseen, but not until recently es- 

 tablished in a satisfactory manner. The other crucial 

 point has been determined mostly by Dr. Fischer himself. 

 His early observations on a voyage to the West Indies in 

 S.M.S. Moltke (1885-86) and his subsequent work during 

 the Plankton Expedition, taken together with the researches 

 of Russell and others, testify abundantly to the existence of 



