157 



Another very interesting and suggestive discovery was a Crinoid, ths 

 tUiizocrinus lofotensU, a stalked starfish, belonging to the Apiocrinidse, a family 

 which flourished during the Oolitic period, and appeared to have become almost 

 extinct before the formation of the older Tertiaries. It was found originally off 

 the Lofoden Islands, by Sars, and it has since been dredged off the North of 

 Scotland and the coast of Florida. In the expedition of 1869 eight species of 

 Mollusca were found which were supposed to have become extinct during the 

 tertiary period. 



Besides these fossil forms, which have an interest of their own, a great 

 abundance and variety of animal life has been found at the greatest depths 

 which have yet been investigated. Considering how fragmentary these investi- 

 gations have yet been and what mere scraps of the vast ocean depths have been 

 included in them, some idea of the richness of the harvest yet to be gathered 

 may be formed from the fact that in the expedition of 1869, of mollusca alone, 

 one hundred and seventeen species were added to the fauna of the British seas, 

 being an addition of more than a fourth to the number previously known. Of 

 these one hundred and seventeen species, fifty-six were new to science. 



These investigations have caused a great change in our ideas on another 

 point — the influence of pressure at great depths on animal life. So far from 

 this pressure being, as was supposed, almost incompatible with it, there seems 

 reason to believe that it has little influence on animals which have no air cavaties 

 but whose bodies consist entirely of solid and liquid parts. Creatures which 

 had been previously known t« inhabit depths of forty or fifty fathoms have been 

 brought up from a depth of 2| miles, and these not simple forms of life, but 

 highly organised animals. There seems no reason to doubt that varied and 

 abundant fonns of animal life will be found at even much greater depths when 

 we are able to explore them. 



There is still considerable difference of opinion as to the food of animals 

 in deep water. Plants which convert inorganic matter into forms fitted to 

 sustain animal life are wanting. Mr. J. Gwyn Jeffreys says that iu the cruise 

 of the "Porcupine" in the North Atlantic, in 1869, he could not detect the 

 slightest trace of any vegetable organism at a greater depth than fifteen feet. 

 The higher animals no doubt feed on the lower, but whether these in their 

 simplest forms obtain sufficient nutriment from the organic matter derived from 

 the decomposition of animals and plants — and which is found to exist in appre- 

 ciable quantity in water at all depths — or whether they are able to draw 

 nutriment directly from the inorganic world is still matter of debate. 



Connected with this question of food is that of light. It has been assumed 

 that at these great depths there must be profound darkness, but as animal» 

 bright in colour, and possessing large and highly organised eyes, have been 

 found inhabiting them, some doubt has been thrown on this assumption^ 



