UROWxVj ON DISCOLORATION OF THE ARCTIC SEAS. 245 



nieuts. On the evening of the 4th of June, 1867, in latitude 

 67° 26' N., the sea was so full of animal (and diatomaceous) 

 life that in a few minutes upwards of a pint measure of En- 

 tomostraca, MedusEe, and Pteropoda would fill the towing- 

 net. The temperature of the sea was then, by the most 

 delicate instruments, found to be 32'5° Fahr., and next 

 morning (June 5th), though the air had exactly the same 

 temperature, no ice at hand, and the ship maintained almost 

 the same position as on the night previous, yet the surface 

 temperature of the sea had sunk to 27'5° Fahr., and was clear 

 of life — so much so, that in the space of half an hour the 

 towing-net did not capture a single Entomostracon, Medusa, 

 or Pteropod. I also found that this swarm of life ebbed and 

 flowed with the tide, and that the Avhalers used to remark 

 that whales along shore were most frequently caiight at the 

 flow of the tide, coming in with the banks of whales' food. 

 This mass of minute life also ascends to the surface more in 

 the calm arctic nights when the sun gets near the horizon 

 during the long, long summer. In 1860 I was personally 

 acquainted with the death of thirty individuals of the " right 

 whalebone whale" {Balcena mysticeius, L.), and of this num- 

 ber fully three fourths were killed between ten o'clock p.m. 

 and six o'clock a.m., having come upon the " whaling 

 grounds" at that period (from amongst the ice where they had 

 been taking their siesta) to feed upon the animals which 

 were then swarming on the surface, and these again feeding 

 on the Diatomaceee found most abundantly at that time in 

 the same situations. I would, however, have you to guard 

 against the supposition, enunciated freely enough in some 

 compilations, that the whales' food migrates, and that the 

 curious wanderings of the whale north, and again west and 

 south, is due to its " pursuing its living ;" such is not the 

 case. The whales' food is found all over the wandering 

 ground of the Mysticete, and in all probability the animal 

 goes north in the summer in pursuance of an instinct im- 

 planted in it to keep in the vicinity of the floating ice-fields 

 (now melted away in southern latitudes) ; and again it goes 

 west for the same purpose, and finally goes south at the ap- 

 proach of winter — but where, no man knows. There are 

 some other streaks of discoloured water in the Arctic Sea, 

 known to the whalers by various not very euphonious names, 

 but these are merely local or accidental, and are also wholly 

 due to Diatomacese, and with this notice may be passed over 

 as of little importance. I cannot, however, close this paper 

 without remarking how curiously the observations I have 

 recorded afford illustrations of representative species in dif- 



