CHAP, u.] THE CRUISE OF THE ' LIGHTNING: 51 



determine with accuracy the conditions and distribution of 

 Animal Life at great depths in the ocean ; I now resume the 

 facts and considerations which lead me to believe that researches 

 in this direction promise valuable results. 



All recent observations tend to negative Edward Forbes's 

 opinion that a zero of animal life was to be reached at a depth 

 of a few hundred fathoms. Two years ago, M. Sars, Swedish 

 Government Inspector of Fisheries, had an opportunity in his 

 official capacity of dredging off the Loffoten Islands at a depth 

 of 300 fathoms. I visited Norway shortly after his return, and 

 had an opportunity of studying with his father, Prof. Sars, some 

 of his results. Animal forms were abundant ; many of them 

 were new to science ; and among them was one of surpassing 

 interest, the small Crinoid of which you have a specimen, and 

 which we at once recognized as a degraded type of the APIO- 

 CEINID^E, an order hitherto regarded as extinct, which attained 

 its maximum in the Pear-encrinites of the Jurassic period, and 

 whose latest representative hitherto known was the Bourguetti- 

 crinus of the Chalk. Some years previously, M. Absjornsen, 

 dredging in 200 fathoms in the Hardangerfjord, procured several 

 examples of a Starfish (Brisinga) which seems to find its nearest 

 ally in the fossil genus Protaster. These observations place it 

 beyond a doubt that animal life is abundant in the ocean at 

 depths varying from 200 to 300 fathoms, that the forms at these 

 great depths differ greatly from those met with in ordinary 

 dredgings, and that, at all events in some cases, these animals are 

 closely allied to, and would seem to be directly descended from, 

 the fauna of the early Tertiaries. 



I think the latter result might almost have been anticipated ; 

 and probably further investigation will add largely to this class 

 of data, and will give us an opportunity of testing our deter 

 mination of the zoological position of some fossil types by an 

 examination of the soft parts of their recent representatives. 

 The main cause of the destruction, the migration, and the extreme 

 modification of Animal types, appears to be change of climate, 

 chiefly depending upon oscillations of the earth's crust. These 

 oscillations do not appear to have ranged, in the northern portion 



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