in the Depths of the Sea. 435 



Generally it seems to consist of soft materials or so-called 

 clay, but frequently also of harder clay mixed with sand, of 

 sand and gravel or stones of different sizes, and also of the 

 bare rock. It is only on this last kind of bottom (big stones 

 or the firm rock) that the great corals sit and grow, among 

 which numerous animals live that are never found on a soft 

 bottom. 



I shall now shortly mention some of the latest opinions ad- 

 vanced on the extent of animal life in the depths of the sea. 



Keferstein (/. c. p. 1095) deduces, from the soundings most 

 recently made at great depths, the following among other 

 conclusions : — " That the animals there found consist of few 

 species, but of many individuals : exactly as has been ob- 

 served in the arctic zone." Again (p. 1097) : — "At moderate 

 depths of about 300-500 fathoms there seem to be the fewest 

 inhabitants." Neither of these statements agrees quite with 

 the abundance both of species and individuals which we find, 

 according to the observations referred to, to be living on our 

 coast at these very depths. 



Loven (Trans. Scand. Naturalists, Stockholm, 1863, p. 384) 

 has expressed opinions on the range of animal life in the depths 

 of the sea, founded apparently in great measure on the sound- 

 ings of the Swedish Expedition to Spitzbergen. He affirms 

 that from 60 to 80 fathoms, down to the greatest depth at 

 which we have hitherto known animal life to exist, the bottom 

 of the sea is covered with a fine mud, which is commonly called 

 clay, and there prevails, from pole to pole, in all latitudes, a 

 fauna of the same common character, of which some species 

 are very widely distributed. 



That in all the seas of the world, from pole to pole, in all 

 latitudes, there should exist a deep-water fauna of the same 

 common character, seems for the moment nothing else than an 

 hypothesis for which he who advances it is responsible ; how- 

 ever, I will not entirely deny the possibility that at the greatest 

 depths there may be a greater uniformity in the fauna than 

 has hitherto been admitted. But I may remark on this sub- 

 ject that, with the exception of the North Sea, we know next 

 to nothing of the fauna of the rest, especially of the equatorial 

 seas ; and therefore next to nothing is known of its " common 

 character." 



The only point Loven advances in support of his assertion 

 is " that in the Antarctic Sea are found forms of Mollusks and 

 Crustacea which seem in part to agree generically, and in part 

 to be almost (!) specifically identical with northern and arctic 

 forms." A certain agreement in physiognomy between the 

 faunas of the Arctic and Antarctic Seas is readily admitted, 



33* 



