7 



,\ UFK. 



Thw was in evidence of the prevalence of life at that 

 depth tli.it muM not be readily net wide. 



Yd dc.-piu- tin- many indications that had been per- 

 ceived of the exi- * dep-ea fauna very little 

 unprewion was made on tin- min-l- of naturalists, and, 

 up to 1866. it was generally lielicved that the field 

 below (he 3110 fathom lino was barren of animal life. 

 Tbi theory was advocated by Edward Forbes, as a 

 result of his researches in the JSgean Sea, and was 

 generally accented, tho facte to the contrary l>cing 

 i|tiiftly ignored. The Mediterranean, indeed, is some- 

 what barren at great di>|<th.. though tin- existence of 

 deep-sea life tlu-rv lias since l>een fully demonstrated. 



re this date, in fad, animal life had been shown 

 to exist off the coast of Spitsbergen at depth- of IIKHI 

 and 14o-> fathoms, ami tin- Profs. Sure, father and son, 

 had made a series of systematic researches at consider- 

 able depths off the Norwegian coast These were fol- 

 lowed by similar researches made in IN'.; l>y Mr. L. F. 

 irtalcti, of tlir I'. S. coast survey. His explora- 

 tions were made off the southern coast of the United 

 States, and reached a depth of r.-u fathoms. In the 

 succeeding year the ligDtfat was sent out by the 

 British almiralty to drcdirc. under the scientific direc- 

 tion of l>r. Car|H'iitcr and Prof. ('. \Vyville Thompson. 

 In this expedition a depth of 650 fathoms was reached. 

 The I >ctter adapted Porcupine, sent out in 1 869, 

 dredged to a depth of 1470 fathoms off the coasts of 

 In-lain! an. I Scotland, and, in her second voyage, 

 reached over :M<Ki fathoms in the Bay of Biscay. At 

 this great depth (2} miles) 'life was found to exist 

 abundantly, and animal forms from the protozoa to 

 the mollusca were brought up. 



During December, 1871, and in the early months of 

 1-7J the coast-survey steamer llassler conducted a 

 scries of deep-sea dredgings. under the scientific direc- 

 tion of Louis Agassis. In 1*71 the U. S. Fi.-h 

 ( '.mi mission was organized, and from that time for- 

 ward made deep-sea exploration an important part 

 of its labors, under the direction of Prof! A. E. Ver- 

 rill, who had been engaged in labors of this kind 

 since l-< 1 



But the most important exploring expedition of this 

 kind that has been made up to the present time is that 

 of the Challenger, a vessel sent out in 187:2 by the 

 English government for the purpose of dredging the 

 depths iii' the great oceans. The Challenger traversed 

 the Atlantic ami the Pacific in various directions, 

 crowing the former ocean five times, her total length 

 of voyage being li'.i.OOO miles. She returned in May. 

 Imnging an exceedingly rich zoological collection, 

 which has been carefully worked up by noted special- 

 ist*, whose labors are represented by mure than :;n 

 bulky volumes. Un three occasions the Challenger' I 

 dredge reached a depth of over 3000 fathoms (about 

 31 miles), and in every ease living forms were brought 

 up from this extreme depth. The deepest sounding 

 made was 4.")7.~> fathoms. For further particulars see 

 article Duma in Ksryrt.oi'.EPlA BlUTANNICA. 



Since the date of the Challenger voyage several im- 

 portant dredging explorations have been undertaken. 

 Norwegian expedition! wen- sent into the northern 

 can in IsTi'.. 1S77, and 1S7S. The Germans, the 

 Italians, and the French followed the same example, 

 the voyage ol the French ship Talisman, in 1883, from 

 the coast of Morocco to the Azores and the Sargasso 

 Bea, having yielded highly valuable results. The 

 Ani'ii-Mii- Live (NTH <i|iially active. From ]S77 to 

 1880 the -i. amer Blake was engaged in deep-sea ex- 

 ploration'- in the reirii'ii of the West India islands and 

 the Gulf ol Mexico. The-c researches, under the 

 K-ientifx dim-linn of Mexandcr Agassis, were fruitful 

 in results, a summary of which has been recently given 

 to the world in two highly interesting volumes. In 

 the explorations of the Itlakc important modifications 

 of the drcdiriiif apparatus wen- made. The dredge 

 naed lor deep sea work is necessarijy made much 

 larger than the original Ball dredge, being about 4) ft. 



long and 1} ft. wide. In addition to the collectiiif- 



B| strand- ol' teased out hemp attached j 

 very serviceable in clitani:lini: slar-fish. corals, and 

 other spiny inhabitants of the great deep. The 

 dredge, however, is now in part superseded by the 

 U-ain trawl, which under certain circumstances prove- 

 more senrioeablc. A trawl, of al>oul !."> ft. in length. 

 was used occasionally by the Challenger, and a similar 

 implement is used almost exclusively by the United 

 State- Fish Commission The immon incuts effected 

 in the lil.ikc explorations were to make tin- i wain trawl 

 reversible, to alter the dredge so as to prevent it bury- 

 ing itself in the mud of soft bottoms, to substitute 

 wire for heni|>cn rope, and to modify the method- of 

 hauling and reeling, these various changes adding 

 greatly to the efficiency of the apparatus. 



In 1SS4 the steamer Fish-hawk was built for the 

 dredging and hatching operations of the Fish Commis- 

 rioflL I'ut her .-mall si/.c unfitting her for deep-sea 

 work she was superseded by the Albatross, the best- 

 cijuipped dredger for deep-sea work in existence. In 

 her first voyage, in 1883, this vessel made a successful 

 trawl in the Atlantic of '-".M'.i fathoms. At present 

 (1888) the Albatross is engaged in an extended voyage 

 of exploration, and is employed in dredging in the 

 Pacific, off the western coast of America. Very in- 

 teresting results may reasonably be expected from this 

 expedition. 



This rapid survey of the history of the exploration 

 of the ocean depths may be followed by an equally 

 concise description of the zoological results. These 

 havt been extensive and important, and have alto- 

 gether changed the views of naturalists as to the 

 limits of ocean life. It is now known that instead of 

 living beings being confined to the littoral zone and to 

 the ocean surface, they exist in abundance at the 

 greatest depths yet examined, every order of life below 

 the air-breathers being represented, and the variety of 

 species being possibly as great as that on the surface. 

 It must be borne in mind that what basso far been 

 done is but a beginning in this work. The dredge has 

 swept at the most a few square miles of an ocean-floor 

 represented by millions of square miles, and explora- 

 tion must be prosecuted for centuries ere any complete 

 conception of its zoology can be attained. So far no 

 part of the ocean is better known in regard to its 

 marine products than that adjoining the Atlantic coast 

 of the United States. The diligent labors of explorers 

 have given us much knowledge concerning both the 

 littoral and the deep-sea life of this region of the 

 waters. 



Among the specimens brought up by the dredge are 

 representatives of every elass of marine life, including 

 corals, sponges, echinodenns, annelids, crustacea. mol- 

 la-ks. and fishes, all of which, except the latter, exist 

 at the greatest depths reached by the dredge. Fi.-hcs 

 have Ix-en captured at a depth of 2900 fathoms, and 

 probably reach as low as the others. As to the vast 

 mill stretch of the ocean, between the range of surface- 

 forms and the bottom, nothing definite is known con- 

 cerning its life forms. There is some reason to believe 

 that life is confined to the surface and the bottom re- 

 gions, and that the intermediate zone is barren ; but 

 the researches as yet made have been insufficient to 

 determine this satisfactorily. The most abundant or- 

 ganic deposits on the ocean bottom are made by minute 

 creature.-, the Uadiolaria and Foraminifcra, whose re- 

 mains form a thick layer of calcareous ooze, which is 

 inhabited abundantly by the shelled animals. (See 

 I'AI inr OIT.VN in Kv v< i .<>I'.EI>I \ MIUTANNICA.) 

 In those regions of the bottom wanting this ooy.c the 

 animal forms are ehietly those without shells, such as 

 the Annelida and tint I Jolothuroidea. 



The variety of animal forms that has been brought 

 up from the ocean bottom is far too great for any at- 

 tempt to particularize, and we can but give a general 

 description of their characteristics. At first it was 

 imagined by many that the deep sea would yield to us 



