NOVEMBER 24, 1899. ] 
sition of terrigenous rocks and minerals in 
deposits nearer continental shores. There 
is thus a striking difference between the 
average chemical and mineralogical compo- 
sition of Terrigenous and Pelagic Deposits. 
It would be extremely interesting to have 
a detailed examination of one of those deep 
holes where a typical Red Clay is present, 
and even to bore some depth into such a 
deposit if possible, for in these positions it 
is probable that not more than a few feet of 
deposit have accumulated since the close of 
the Tertiary period. One such area lies to 
the south-west of Australia, and its exami- 
nation might possibly form part of the pro- 
gram of the approaching antarctic explora- 
tions. 
Life on the Ocean-floor. 
It has already been stated that plant-life 
is limited to the shallow waters, but fishes 
and members of all the invertebrate groups 
are distributed over the floor of the ocean 
at all depths. The majority of these deep- 
sea animals live by eating the mud, clay, or 
ooze, or by catching the minute particles of 
organic matter which fall from the surface. 
It is probably not far from the truth to say 
that three-fourths of the deposits now coy- 
ering the floor of the ocean have passed 
through the alimentary canals of marine 
animals. These mud-eating species, many 
of which are of gigantic size when compared 
with their allies living in the shallow coastal 
waters, become in turn the prey of numer- 
ous rapacious animals armed with peculiar 
prehensile and tactile organs. Some fishes 
are blind, while others have very large eyes. 
Phosphorescent light plays a most impor- 
tant réle in the deepsea, and is correlated 
with the prevailing red and brown colors 
of deep-sea organisms. Phosphorescent or- 
gans appear sometimes to act as a bull’s-eye 
lantern to enable particles of food to be 
picked up, and at other times as a lure ora 
warning. All these peculiar adaptations 
indicate that the struggle for life may not 
SCIENCE. 
709 
be much less severein the deep sea than in 
the shallower waters of the ocean. 
Many deep-sea animals present archaic 
characters ; still the deep sea cannot be 
said to contain more remnants of faunas 
which flourished in remote geological 
periods than the shallow and fresh waters 
of the continents. Indeed, king-crabs, 
Lingulas, Trigonias, Port Jackson sharks, 
Ceratodus, Lepidosiren and Protopterus prob- 
ably represent older faunas than anything 
to be found in the deep sea. 
Sir Wyville Thompson was of the opinion 
that, from the Silurian period to the present 
day, there had been as now a continuous 
deep ocean with a bottom temperature os- 
cillating about the freezing-point of fresh 
water, and that there had always been an 
abyssal fauna. I incline to the view that in 
Paleozoic times the ocean-basins were not 
so deep as they are now; that the ocean 
then had throughout a nearly uniform 
high temperature, and that life was either 
absent or represented only by bacteria 
and other low forms in great depths, as is 
now the case in the Black Sea, where life is 
practically absent beyond 100 fathoms, and 
where the deeper waters are saturated with 
sulphuretted hydrogen. This is not, how- 
ever, the place to enter on speculations con- 
cerning the origin of the deep-sea fauna, 
nor to dwell on what has been called ‘ bipo- 
larity’ in the distribution of marine or- 
ganisms. JoHN Murray. 
( To be Continued. ) 
THE EARLY PRESIDENTS OF THE AMERICAN 
ASSOCIATION. 
IV. 
LOVERING.* 
Lovering + was born in Charlestown, 
Massachusetts, now a portion of Boston, in 
_* A portrait of Joseph Lovering is printed as frontis- 
Mego sketch in Popular Science Monthly, with an en- 
graved portrait on wood, Vol. XXXV., p. 690, Sep- 
tember, 1889. Also see article in Scientific American, 
February 27, 1892, with a half-tone portrait. 
