198 



♦ KNOWLEDGE ♦ 



[Aug. 18, 1882. 



the IcXthyococcus ornatus and Si-oyn'.us Ranntiquii they aro spe- 

 cially abundant. In one ppooics of the former a largo luminous 

 spot occurs up>in the fn'iit of the houd. 



The distinguished naturalist of the ChalUn<)er expedition, Willo- 

 moes-Suhm, now deceased, saw Scopelius phosphorescent in tho 

 night, of which he says : " One of them hung in tho net like a 

 shining star as it came out of the darkness. Possibly the scat of 

 the light is in the peculiar side organs, and it may bo that Uiis 

 phosphorescence is the only source of light in tho great depths of 

 the 8«^a." 



The thought that in the dark abysses of the deep sea every 

 animal carries its lantern, as themiuercarries his lamp on hisheail, 

 i« a very fascinating one ; and, indeoii, Uerr Willemocs-Suhm 

 observi-d several other fishes that were provided on tho smooth 

 head and on the head-beard with a " remarkably largo sense organ." 

 Valenciennes has also remarked of the g<nms Hemirainphus that it 

 bears a strongly glittering phosphorescent pustule on the tip of its 



LtJUINOrs SHARK 

 (Squalui futyens). 



FISH WITH I'HOSPMOBESCKNT SPOTS 



{Ichlhyococcus ornattu). 



" When tho larger specimen, taken nt night, was removed into a 

 dark apartment, it afforded a very extraordinary spectacle. Tho 

 entire inferior surface of the body and head omitted a vivid and 

 greenish phosphorescent gleam, imparting to the creature, by its 

 own light, a truly ghastly and terrific appearance. Tho luminous 

 effect was constant, and not prceptibly increased by agitation or 

 friction. I thought at one time it shone brighter when tho fish 

 struggled, but I was not satisfied that such was the fact. When 

 the shark expired (which was not until it had been out of the water 

 more than three hours) tho luminous appearance faded entirely from 

 tho abdomen, and more gradually from other parts, lingering tho 

 longest around the jaws and on the fins. 



" The only part of the under surface of the animal which was 

 free from luminosity was the black collar around the throat j and 

 while the inferior surface of tho jiectoral, anal, and caudal fins shone 

 with splendour, tho suiwrior surface (including the upper lobe of 

 the tail fin) was in darkness, as also were the dori-al fins, back, and 

 summit of the head. 



" 1 am inclined to believe that the luminous power of this shark 

 resides in a peculiar secretion from the skin. It was my first im- 

 pression that tlio fish had accidentally contracted somo phosphores- 

 cent matter from the sea, or from tho net in which it was captured, 

 but the most rigid investigation did not confirm this suspicion, while 

 the uniformity with which the luminous gleam occupied certain 

 portions of the body and fins, its perfornmnco during life, an* 

 decline and cessation upon the approach and occurrence of death, 

 did not leave a doubt in my mind that it was a vital principle essen- 

 tial to the economy of the "animal. The smallncss of tho fins would 

 ap])car to denote that this fish is not active in swimming ; and, since 

 it is highly predaceous, and evidently of nocturnal habits, wo may 

 perhaps indulge in tho hypothesis that the phosphorescent power it 

 possesses is of use to attract its prey, upon the same principle as 

 the Polynesian Islanders and others employ torches in night 

 fishing."— Scicn(t/ic American. 



N 



Among the fishes discovered by the Challenger expedition was tho . 

 Echiotoma microdon, a dark fish from two miles beneath tho surface. 

 Helow its eyes were two luminous B|>ots; a narrow elongated one | 

 above the maxillary, and a small, short organ nearer the eye. j 



Another species, the ilieripnun, had long fringed barbels ; lumi- i 

 nous spoti above the maxillary, small and round. This was found ' 

 •m the .\niitnilian coast in 2,150 fathoms. , 



.\ momatoid fish, Uathyophig, found over three miles below the 

 •urface, had long barbels ; small luminous organs above the middle 

 of the upper jaw, and a number of others along each side of the 

 aljdomcn ; also on the tail and outer ventral rays. 



In the Ipnops tho Ijody was long, covered with cylindrical scales, 

 and devoid of luminous organs. ITic head was depressed, long, and 

 djiatulate, its entire upper surface occupied by a remarkable ! 

 phosphorescent orfjan that was longitudinally divided into two 

 symmetrical halves. ] 



The most remarkable light-giving fish, however, is a shark, a 

 species of HcymnvM, and allied to our morse of the southern coast, 

 discovered by Dr. Bennett in Australian waters. The light in this i 

 casQ was tmivcnal. Id relation to bis find, Dr. Bennett gays : — I 



THE CHARMS OF SWORDFISHING. 



()W that whaling has to so largo an extent ceased to bo the- 

 important industry it once was, the most exciting sport which 

 the hardy fishermen of Nantucket and Martha's Vineyard find loft 

 to them" is tho catching of swordfish. Tho name of this fish 

 describes its most peculiar feature, the pospcssion of a long and 

 sharp sword attached to tho snout, and, although it cuts but a 

 small figure beside the whale in point of size, it does not yield to 

 the more ponderous deni<.en of tho deep in the reckless daring 

 with which it fights for life when attacked. A schooner dcsignefl- 

 for the copture of swordfish is provided with a " pulpit," 

 uhich is the name given to a littlo jilatform built on tho 

 . xiremo point of the bowsprit, about three and one-half feet 

 ill height, and having a semi-circular iron strap, supported by 

 blanchions. When a fish is sighted by tho look-out, who stands 

 on a sort of platform affixed to tho head of tho foremast, 

 the vessel is brought as near as possible, nnd then the captain takes 

 his place on tho " pulpit," armed with a harpoon. The barb of the 

 harpoon, which is about six inches in length, is backed with an iron 

 ]iocket in which the iron shank rests, and the shank is attached to 

 the vessel by a short line, by which it is freed from the fish when ho 

 is struck. In order to secure a great swordfish the barb must bo 

 driven right tlirongh him. Then when the shank comes out and tho 

 lino is pulled taut, the barb " toggles on," as the fishermen call it— 

 that is to say, it catches on tho other side, and no effort of the 

 victim will free him from tho line. When the fish feels the sharp 

 iron penetrating his Hcsh, ho usually springs half out of tho sea, 

 then plunges back into tho depths and makes off so fast that water 

 has to be poured over the line attached to the harpoon as it runs out 

 from the boat to prevent its catching fire. When tho fish finally comes 

 to a standstill, tho men begin to draw in the line. Sometimes al will go 

 well until the monster is brought along*.iile, while again tho fish, after 

 being drawn well in, will dash off afresh with such speed that the 

 men hauling tho line will bo shot over the side into the sea. hven 

 when he has finally been dragged near tho vessel, tlio fish may 

 suddenly summon all his energy and rush upon tho craft with a 

 violence which will shako it from stem to stern, and if ho succeeda 

 in hitting it with his sword, may drive a hole through which the- 

 water will pour in. Gradually, however, his Mreiigth is exhausted 

 with tho constant loss of blood, nnd at last he is hauled alongside, 

 when two iron " landers," resembling boat-hooks, and having curve* 

 steel hooks at tho extremities, are handed over the side and thrust 

 into his gills. By the use of these his great head is held, while » 

 stalwart sailor climbs down over tho side with the " thumper, ' 

 a weapon between a tomahawk ond a sledge-lmmnier, and 

 gives him a scries of ponderous blows between tho eyes, 

 despite his struggles. Then a great hook is got over bia 



