CHAP. II.] THE CRUISE OF THE ‘ LIGHTNING,’ Dall 
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 zevo_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 Apro- 
CRINID, 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- 
erinus 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 
E 2 
