290 lioyal Society : — On the Xaturc of the 



nounced, while perfect shells of Olohigerina almost disappear, 

 fniguunits bet-omo smaller, and calcareous mud, structui'eless and 

 in a line state of division, is in greatly preponderating proportion" 

 (^* Depths of the Sea,' p. 410). These facts seem to me to mark 

 very strongly the distinction between the living surface-layer and 

 the ikdd sub-surface layer, and to show that there is nothing in 

 the condition of the Deep iSea that is likely to prevent or even to 

 retard the decomposition of the dead sarcodtj bodies of Gluhii/eruur, 

 AVe know that oxygen is present in Oceanic water, even to its 

 abyssal depths, in sutllcieut proportion for the maintenance of 

 animal life ; and what sulKces for this, must be adeipiate to 

 promote the decomposition of organic matter. There is, moreover, 

 a significant indication of the undecomposed condition of the 

 sarcode bodies of the Globic/erince of the surface-layer, in the fact 

 that they serve as food to various higher animals which live on the 

 same bottom. This was first pointed out by Dr. Wallich, who 

 found that the contents of the stomachs of the OphiocomcE brought 

 up in his ll^GO-fathoms sounding consisted of a number of fresh- 

 looking Globii/tritue more or less broken up, minute yellow amor- 

 phous particles, and a few oil-globules (' North- Atlantic 8ea-bed,' 

 p. 145). And 1 have subsequently verified his statement in many- 

 other cases *. 



It seems to me clear, from the foregoing facts, that the onus 

 prohaiidi rests on those who maintain that the Glolii(/erin(p. do 

 not live ou the bottom ; and such proof is altogether wanting. 

 The most cogent evidence iu favour of that proposition would be 

 furnished by the capture, floating in the upper waters, of the 

 large thick-shelled specimens which are at present only known as 

 having been brought up from the sea-bed. And the capture of 

 such specimens would only prove that even in this condition the 

 Glohujerime can float; it would not show that they cannot also live 

 on the bottom. 



That the Glohirjerince not only live, but propagate, on the Sea- 

 bottom, is indicated by the presence (as already stated) of enor- 

 mous multitudes of very young specimens in the water immediately 

 overlnng it. And thus all we at present know of the life-history 

 of this most important type seems to lead to the conclusioji, that 

 whilst in the earlier stages of their existence they are inhaliitants 

 of the upper waters, they sink to the bottom on reaching adult age, 

 in consequence of the increasing thickness of their shells, that they 

 propagate there (whether by gemmation or sexual generation is not 

 known), and that the young, rising to the surface, repeat the same 

 history. 



I now proceed to show that the relation between the surface- 

 fauna and the bottom-deposit is by no means so constant as Prof. 

 Wyville Thomson and Mr. Murray atlirm it to be. 



* Thus ilnn indirectly draws sustenance from the Glohi(jcrincB ; for the Ctxl 

 which he fishes on the Faroe Banks chiefly live on the Opkiocoma which swarm 

 there, these again on the Glohiyerince, whilst tlio Glohic/eriiKe seem to draw 

 their sustenance from the organic matter universally dilTused througli soa- 

 water, making it a very dilute broth ! 



