TRANSACTIONS OF SECTION EK, ( 
account for these layers by referring them to changes in the condition of the 
surface waters, but in other situations it seems necessary to call in elevations and 
subsidences of the sea-floor. 
ff the whole of the carbonate of lime shells be removed by dilute acid from a 
typical sample of Globigerina Ooze, the inorganic residue left behind is quite 
similar in composition to a typical Red Clay. This suggests that possibly, owing to 
some hypogene action, such as the escape of carbonic acid through the sea-floor, 
a deposit that once was a Globigerina Ooze might be slowly converted into a Red 
Clay. However, this is not the interpretation which commends itself after an 
examination of all the data at present available; a consideration of the rate of 
accumulation probably affords a more correct interpretation. It appears 
certain that the Terrigenous Deposits accumulate much more rapidly than 
the Pelagic Deposits. Among the Pelagic Deposits the Pteropod and Globi- 
gerina Oozes of the tropical regions, being made up of the calcareous shells of 
a much larger number of tropical species, apparently accumulate at a greater rate 
than the Globigerina Oozes in extra-tropical areas.  Diatom Ooze being composed 
of both calcareous and siliceous organisms has again a more rapid rate of deposition 
than Radiolarian Ooze. In Red Clay the minimum rate of accumulation takes 
place. The number of sharks’ teeth, of earbones and other bones of Cetaceans, 
and of cosmic spherules, in a deposit may indeed be taken as a measure of the rate 
of deposition. These spherules, teeth, and bones are probably more abundant 
in the Red Clays, because few other substances there fall to the bottom to cover 
them up, and they thus form an appreciable part of the whole deposit. The 
volcanic materials in a Red Clay having, because of the slow accumulation, been 
for a long time exposed to the action of sea-water, have been profoundly altered. 
The massive manganese-iron nodules and zeolitic crystals present in the deposit 
are secondary products arising from the decomposition of these volcanic materials, 
just as the formation of glauconite, phosphatic, and calcareous and barytic nodules 
accompanies the decomposition of terrigenous rocks and minerals in deposits nearer 
continental shores. There is thus a striking difference between the average 
chemical and mineralogical composition 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 examination micht 
possibly form part of the programme of the approaching Antarctic explorations. 
Life on the Ocean-floor, 
It has already heen 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 covering 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 numerous rapacious animals armed with 
peculiar prehensile and tactile organs. Some fishes are blind, while others haye 
very large eyes. Phosphorescent light plays a most important rd/e in the deep 
sea, and is correlated with the prevailing red and brown colours of deep-sea 
organisms. Phosphorescent organs appear sometimes to act as a bull’s-eye lantern 
to enable particles of food to be picked up, and at other times asa lure or a warning. 
All these peculiar adaptations indicate that the struggle for life may be not much 
less severe in 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 ceological 
periods than the shallow and fresh waters of the continents. Indeed, kine-crabs 
