478 



Messrs. Carpenter, Jeffreys, and Thomson [Xov. 18, 



intelligible that a world of animals should live in these dark abysses : but 

 it is a necessary condition that they should chiefly belong to a class capable 

 of being supported by absorption through the surface of matter in solution, 

 developing but little heat, and incurring a very small amount of waste by 

 any manifestation of vital activity. According to this view, it seems highly 

 probable that at all periods of the earth's history some form of the Pro- 

 tozoa (Rhizopods, Sponges, or both) predominated over all other forms 

 of animal life in the depths of the Sea, whether spreading, compact, and 

 reef-like, as in the Laurentian and Palaeozoic Eozoon, or in the form of 

 myriads of separate organisms, as in the Globigerince and Ventriculites of 

 the Chalk"*. 



129. During each Cruise of the 'Porcupine,' samples of Sea-water ob- 

 tained from various depths, as well as from the surface, at stations far re- 

 moved from land, were submitted to the Permanganate test after the method 

 of Prof. W, A. Miller, with an addition suggested by Dr. Angus Smith 

 for the purpose of distinguishing the Organic matter n a state of decom- 

 position from that which is only decomposable ; with the result of showing 

 the uniform presence of an appreciable quantity of matter of the latter kind, 

 which, not having passed into a state of decomposition, may be assimilable 

 as food by animals, — being, in fact, Protoplasm in a state of extreme dilution. 

 — Until, therefore, any other more probable hypothesis shall have been 

 proposed, the sustenance of Animal life on the ocean-bottom at any depth 

 may be fairly accounted for on the supposition of Prof. Wyville Thomson, 

 that the Protozoic portion of that Fauna is nourished by direct absorption 

 from the dilute Protoplasm diffused through the whole mass of Oceanic 

 waters, just as it draws from the same mass the Mineral ingredients of the 

 skeletons it forms. This diffused Protoplasm, however, must be continu- 

 ally undergoing decomposition, and must be as continually renewed ; and 

 the source of that renewal must lie in the surface-life of Plants and Ani- 

 mals, by which (as pointed out by Prof. Wyville Thomson) fresh supplies 

 of Organic matter must be continually imparted to the Oceanic waters, 

 being carried down even to their greatest depths by that liquid diffusion 

 which was so admirably investigated by the late Professor Graham. 



130. The analysis of the Gases contained in Sea-water, collected not 

 only at the surface but from various depths beneath it, was systematically 

 carried on during the whole of the Expedition. The results cannot be 

 considered as entirely satisfactory ; since it is by no means certain that the 

 relative proportions of the gases obtained by boiling water taken up from 

 great depths may not have been affected by the liberation of a portion of 

 these gases when the superincumbent pressure was removed. But they 

 will be found extremely suggestive, and seem to have a tolerably definite 

 relation to the Respiration of the Abyssal Fauna. Referring to Appendix I. 

 for a fuller statement of details, we may here call attention to their general 



* " The Depths of the Sea," a Lecture delivered in the theatre of the Royal Dublin 

 Society, April 10, 1869. 



