Feb. II, 1875] 



NATURE 



297 



Vapour ought not to exceed 4°7 grains per cubic foot at a 

 temrerature of 63* F., or 50 grains at a temperature of 65° F. 



IhtmiJity (per cent.) ought not to exceed 73 to 75. 



Carbonic Arid. Respiratory impurity ought not to exceed 

 O-O0O2 per foot, or o'2O0O per 1000 voKimes. 



Talking the mean external air ratio at 0'4O0O per 1000, this 

 would give a mean internal air ratio of . o Gcoo per 1000 

 volumes. 



Feb. 4. — Remarks on Professor Wyville Thomson's Prelimi- 

 nary Notes on the nature of the Sea-bottom procured by the 

 soundings of H.M.S. Chalkiigtr, by William B. Carpenter, 

 F.R.S. 



The author began by referring to two of the questions started 

 and partly discussed in Professor Wyville Thomson's comrauni- 

 cation. 



Tlie first of these questions is, whether the Gloliis^erina; by the 

 accumulation of whose shells the Clobigcrina ooze is being formed 

 on.the deep-sea bottom, live and multiply on that bottom, or pass 

 their whole livts in the superjacent water (especiallyin its upper 

 stratum), only subsiding to the bottom when dead. 



Prof. Wyville Thomson has been led to adopt the latter opi- 

 nion, by the results of Mr. Murray's explorations of the surface 

 and sub-surface waters with the tow-net ; while the close relation 

 which they furlhtr indicate between the surface-fauna of any 

 particular locality and the materials of the organic deposit at the 

 bottom appears to Prof. Wyville Thomson to warrant the con- 

 clusion that the latter is altogether derived from the former. 



The author, without calling in question the correctness of these 

 observations, submitted, first, that they bear a different interpre- 

 tation ; and, second, that this interpretation is required by other 

 facts, of which no account seems to have been taken by Prof. 

 Wyville Thomson and his coadjutor. That the Clobigcrimc lii'c 

 on the Iwtloin only, is a position clearly no longer tenable ; but 

 that they live and multiply in the upper -aciicrs only, and only 

 sink to the bottc m after death, seems to the author a position no 

 more icnable than the preceding ; and he adduces the evidence 

 which appears to him at present to justify the conclusion that 

 whilst the Clobigerina: are pelagic in an earlier stage of their lives, 

 frequenting the upper stratum of the ocean, they sink to the bottom 

 wliilst still living, in consequence of the inci'easing thickness of 

 their calcareous shells, and not only continue to live on the sea- 

 bed, but probably multiply there, — perhaps there exclusively. 



That there is no a priori improbability in their doing so, is 

 proved by the abundant evidence in the author's possession of the 

 existence of foraminiferal life at abyssal depths obtained during 

 the Porcupine expeditions of 1869 and 1870. 



Of the existence of living Globigernuv in great numbers in the 

 stratum of water immediately above the bottom, at from 500 to 750 

 fathoms' depth, the author is .able to speak wiih great positiveness. 

 It several times happened, during the third cruise of the Por- 

 cupine in 1S69, that the water brought up by the water bottle from 

 immediately above lire Clobigerina oois was quite tuibid ; and 

 this turbidity was found (by filtration) to depend, not upon the 

 suspension of amorphous particles difl'used through the water, 

 but upon the presence of multitudes of young Globigerina-, wliich 

 were retained upon the filler, the water passing through it quite 

 clear. The contrast in size and condition between the floating 

 shells and those lying on the bottom immediately beneath them 

 was most complete. 



The author then alluded to the observations of Dr. Wallich, 

 with which his own are in entire accordance, and which leave no 

 reasorrable ground for doubt that the contrast is a consequence of 

 their continued lije. For it is clearly shown, by making thin 

 transparent sections of the thick-shelled Globigerina-, that the 

 change of external aspect is due to the remarkable e.vogenous 

 deposit which is formed, after the full growth of the Globi^^erino 

 has been attained, upon the outside of the proper chamber- 

 wall. This deposit is not only many times thicker than the ori- 

 ginal chamber-wall, but it often contains fl.ask-shaped cavities 

 opening frorrr the exterior, and containing sarcode prolonged into 

 it from the sarcodic investment of the shell From these important 

 observations, it seems to the author an almost inevitable inference 

 that the subsidence of the G/obigcrimv to the bottom is the con- 

 sequence, not of their death, bitt of the increasiirg thickness and 

 weight of their shells, produced by living action. 



That the Globigerina- which have subsided to the bottom con- 

 tinue to live there is further indicated by the condition of the 

 sarcodic contents of their shells. In any sample of Globigerina 

 ooze that the author has seen brought up by the dredge or the 



sounding apparatus, part of the shells (presumably those of the 

 surface-la) er) were filled with a sarcodebody corresponding in 

 condition with that of foraniinifera known to live on the sea-bed, 

 and retaining the characteristic form of the organism after the 

 removal of the shell by dilute acid. In the same sample will be 

 found shells distinguishable from the preceding by their dingy 

 look and greyish colour, by the want of consistence arrd viscidity 

 in their sarcode contents, and by the absence of any external 

 sarcodic investment ; these are presumably dead. Other shells, 

 again, are entirely empty ; arrd even when the surface stratum is 

 formed of perfect Globigeriuce, the character of the deposit soon 

 changes as it is traced downwards. (See " Depths of the Sea," 

 p. 410). These facts seem to the author to mark very strongly 

 the distinction between the living surface-layer and the dead sub- 

 surface layer ; and to show that there is nothing in the condition 

 of the deep sea that is likely to prevent or even to retard the 

 decomposition of the dead sarcode bodies of Globigerimv. There 

 is a significant indication of the undecomposed condition of the 

 sarcode bodies of the Globigerincv of the surface-layer, in the fact 

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

 the same bottom. 



It seems to the author clear, from the foregoing facts, that the 

 onis probandi rests on those who maintain that the Globigerime 

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

 The most cogent evidence in 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 

 Globigeriuis can float ; it would not show that they cannot also 

 live on the bottom. 



That the Globi'^erinii: not only Atr, hai propagate, on the sea- 

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

 enormous multitudes of very young specimens in tlie water imme- 

 diately overlying it. And thus all we at present know of the life- 

 history of this most important type seems to lead to the conclu- 

 sion, that whilst in the earlier stages of their existence they are 

 inhabitants 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. 



The author then proceeded to show that the relation between 

 tlie surface-fauna and the bottom-deposit is by no means as con- 

 stant as Prof. Wyville Thomson and Mr. Murray affirm it to be. 

 It may be taken as proved that there is no want of foramini- 

 feral life in the Medrterranean. To confirm this the author 

 referred to the results obtained by various observers. That 

 Foraminifera, especially Globigerina:, abound in its surface-water 

 at Messina, is testified by Hackel in the passage cited by Prof. 

 Wyville Thomson ; and when it is considered how large an influx 

 of Atlantic water is constantly entering through the Strait of 

 Gibraltar, and is being diffused throughout the Mediterranean 

 basin, and how favourable is its temperature-condition, it can 

 scarcely be doubted that if the doctrine now upheld by Prof. 

 ^V■yville Thomscn were correct, the deposit of Globigctina shells 

 over the whole bottom-area ought to be as abundant as it is in 

 the Atlantic under corresponding latitudes. Yet the author found 

 the deeper btttoms, from 300 fathoms downwards, entirely des- 

 titute of Globigerine as of higher forms of animal life ; and this 

 was also the experience of Oscar Schmidt. 



The author can see no other way of accounting for the absence 

 of Globigerina ooze from the bottom of the Mediterranean, save 

 orr its shallow borders, than by attributing it to the unfavourable 

 nature of the influences affecting the bottom-lip'e of this basin ; 

 that is to say, the gradual settling down of the fine sedimentary 

 deposit which forms the layer of inorganic mud everywhere 

 spread over its deeper bottom ; and thedeficiencyof oxygen and 

 excess of carbonic acid which the author has sho\\n to prevail in 

 its abyssal waters, giving them the character of a stagnant pool ; 

 these influences acting either singly or in combination. 



Another fact to which Prof. Wyville Thomson formerly 

 attached considerable importance as indicative of the bottom- 

 life of the Globigerinir, is unnoticed in his recent communication, 

 viz., the singular limitation of the Globigerina ooze to the " w.ann 

 area" of the sea-bed between the North of Scotland and the 

 I'aroe Islands. Details of the observation will be found in the 

 author's Lightning and Porcupine Reports on the exploration of 

 this region. On the " cold area " the author never found a single 

 Globigerina ; the bottom consisting of sand and gravel, and the 

 Foraminifera brought up from it being almost exclusively those 



