1868.] 



on Deep-sea Dredgings. 



185 



when the bulk of the body is augmented by the ingestion of solid or liquid 

 particles (say the reception of a zoospore of a Protophyte as food, or the 

 filling of the "contractile vesicle" with water from without, which seems 

 to be a sort of respiratory process), just as much pressure will be exerted 

 by the superincumbent liquid in forcing those particles into the body as is 

 exerted upon the exterior of the body in resisting its distension; so that 

 here, again, the influence of that pressure will be practically nil. — If the 

 actions of any purely aquatic Animal of more complex structure be looked 

 at from the same point of view, I am persuaded that it will be found that 

 they are not practically interfered with by fluid pressure to any amount,— 

 such pressure not having any tendency to alter either the general form of 

 the body, or the shape of its softest and most delicate parts, and not inter- 

 fering in the least either with the movements of these parts one upon 

 the other, or with the circulation of fluid in their interior, or with those 

 molecular changes which are concerned in their nutrition. 



II. The results we have obtained fully justify the confident expectation 

 we had formed and expressed (see Appendix), on the basis afforded by 

 the observations of M. Alphonse Milne-Edwards on the Mediterranean 

 Cable, and by the results of the dredgings of M. Sars, jun., that the 

 systematic exploration of the Ocean-bottom, at depths much greater 

 than are usually to be found near land, would bring to light many forms 

 of Animal life, either altogether new to science, or hitherto supposed 

 to be limited to particular localities, or known only as belonging to a Geo- 

 logical epoch supposed to have terminated. For one and the same cast of 

 the dredge, in the singularly productive locality specified in § 16, brought 

 up specimens of the highest interest belonging to each of these categories ; 

 so that if we had been able, by remaining there even for a few days, to 

 work this ground thoroughly, a much larger addition might have been 

 fairly expected from this one spot, — still more, therefore, if the inquiry 

 should be extended over that much wider area in which, as will presently 

 appear, the like conditions prevail. For it must have been a strangely 

 fortunate accident that brought together into our dredge so remark- 

 able a collection of Vitreous Sponges and gigantic Rhizopods (many 

 of them altogether new, and the rest known only as inhabitants of very 

 distant localities, — with the Rhizocrinus previously obtained only in one 

 spot more than 600 miles off), if these were not diffused tolerably abun- 

 dantly as well as widely ; and the probability that they are so rises almost 

 to a certainty, when it is borne in mind that the next dredgefull that was 

 obtained from a bottom similar both in character and in temperature, 

 though at a depth of 120 fathoms greater, and at a distance of 200 miles 

 in a straight line, showed distinct evidence of the prevalence of similar 

 types (§19). 



III. Our researches have conclusively established the existence of a 

 minimum Temperature* at least as low as 32° [0° Cent.] over a considerable 

 * It is obvious that any error in our Thermometers, arising from the pressure of 



