1868.] 



on Deep-sea Dredgings. 



181 



universal assent of Naturalists . It is still urged* that the Globigerince lived 

 at or near the surface, and that they only fell to the bottom after death. 

 And it has been thought by many to be more probable that the Ophiocomce 

 had been entangled by the Sounding-line during either its descent or its 

 ascent through the water, than that they had lived on the bottom. Our 

 Dredge, however, having brought up, from depths of 530 and 650 fathoms, 

 abundance of living Globigerince and Ophiocomce entangled in the recesses of 

 Sponges, with Rotalice attached by shell-substance to the spicules of these 

 Sponges, the statements of Dr. Wallich with regard to these animals, 

 which I had always myself regarded as probable, may now be considered 

 as put beyond reasonable question f. 



The general bearings of the facts thus brought to light, together with 

 those furnished by the earlier observations of Sir John Ross and others, 

 are fully and ably discussed by Dr. Wallich ; but I must content myself 

 with the following citation of his conclusions, referring to his Treatise for 

 the arguments on which they rest : — 



" Basing my arguments, then, on two facts which I venture to hope are 

 unequivocally proved in the preceding pages, namely that highly organized 

 creatures have been captured in a living condition at depths vastly exceed- 

 ing those to which animal life had previously been supposed to extend, and 

 that their presence, when captured, cannot be regarded as an accidental or 

 exceptional phenomenon, it has been my endeavour to establish the follow- 

 ing important propositions : — 



"I. The conditions prevailing at great depths, although differing ma- 

 terially from those which prevail near the surface of the ocean, are not in- 

 compatible with the maintenance of animal life. 



" II. Assuming the doctrine of single specific centres to be correct, the 

 occurrence of the same species in shallow water and at great depths proves 

 that it must have undergone the transition from one set of conditions to 

 the other with impunity. 



"III. There is nothing in the nature of the conditions prevailing at 

 great depths to render it impossible that creatures originally, or through 

 acclimatization, adapted to live under them should become capable of living 

 in shallow water, provided the transition be sufficiently gradual ; and hence 

 it is possible that species now inhabiting shallow water may at some an- 

 terior period have been inhabitants of great depths. 



* See Mr. Gwyn Jeffreys, in ' Annals of Natural History,' 4th series, vol. ii. (October 

 1868), p. 305. 



t I had myself accepted Dr. Wallich's inference in regard to the Ophiocomce on the 

 following grounds : — first, because, having often kept O-phiocomce in an aquarium for 

 several weeks together, I never saw them swim, and do not believe that they are capable 

 of moying in any other way than by crawling over a solid surface ; and second, because 

 I know it to be their habit to cluster round a rope lying along the bottom they fre- 

 quent, — the first I ever saw alive having been obtained for me by the Harbour-master 

 of Plymouth, who sank a rope in a part of the Sound which he knew to be frequented 

 by them, and drew it up again after some hours, covered with Ophiocomce. 



