3G0 



SCANDINAVIAN FISHKS. 



whereas in other fishes, we need hardly say, this gas 

 almost entirely fills the air-bladder. 



MoBius also observes that these fishes are assisted 

 in their flight by the flat shape of the belly, where the 

 lateral lines, which are raised as in the preceding genus, 

 follow the ventral margins. The lateral lines thus, to 

 a certain extent, increase the width of the bearing sur- 

 face. The Avell-developed palatal curtains or transverse 

 dermal folds in the mouth behind the margins of the 

 upper and lower jaAvs, are also of service, for they re- 

 tain the Avater that is enclosed in the cavity of the 

 mouth, thus keeping the branchial lamella' moist during 

 the passage of the fish through the air. 



In many cases fear is probably the first cause of 

 the aerial flight of the Flying-fish: as we have just 

 observed ^vith respect to the Saury, the Fljdng-fish also 

 seeks refuge in the air from its pursuers, especially the 

 Dolphin-fishes (Coryphcena) and Bonitos, or sometimes 

 springs up in terror before the bow of a vessel under way. 



-- / 



i 



Fig. 96. Transverse section of a Flying-fish : u, vertebra?; c, kidneys; 

 ves, air-bladder; g, organs of generation; /, lateral lines; i, intestine. 



After MoBius. 



Often, however, this habit is due to the same instinct 

 tiiat impels the Gai'pike to leap out of the water as if 

 ill sport; and like other fishes that are closely packed 

 in shoals, they often leap in order to escape the crush 

 or to pass one another. They appear on the wing of- 

 tener in stormy weather or a steady breeze than in a 

 (lead calm. They generally keep only a. few feet above 

 the surface; and when they rise higher, as in the cases 

 where they have fallen on the deck of a vessel as much 

 as 5 metres above the water, this is also due, says 

 MoBiu.s, to the influence of the air-currents (fig. 97). 

 The Flying-fish always come on boai-d on the windward 

 side in a fresh breeze and, in most cases, at night, 

 when in s])ite of their large e\ es they cannot see the 

 ship and avoid it. On the windward side of vessels 

 that lia\e sailed during the night througli some ])a.rt of 

 the ocean where Flying-fish abound, spots of blood and 



" Zoologist, 2 ser., vol. VIII (187:!) p. 37.S9. 

 '' Ibid. 1874, p. 3838. 



the scales of Flying-fish are often found in the morning; 

 and when the sailors swab the decks, they sometimes 

 come across no small numbers of Flying-fish, a welcome 

 and agreeable change in the seamen's fare. Some of 

 the Flying-fish have thus been dashed against the ves- 

 sel's side in their rajnd flight and killed: but others 

 have been borne over the buhvarks by the current of 

 air that rushes up the Avindward side of the vessel, 

 and have fallen on deck. 



The small iaw-teeth of the Flving-fish show that 



J ^ CD 



its food must consist of small, weak marine animals of 

 the lower classes. Their pharyngeal apparatus resembles 

 that of the Garpike, there being two upper pharyngeals 

 on each side, the posterior (larger) pair closely united 

 at the mesial line of the palate, and one triangular lo\ver 

 pharyngeal pointed in front, .all closely set A\ith cylin- 

 drical, obtusely pointed teeth. The gill-rakers are 

 also like those of the Garpike, the outer row on the 

 first branchial arch being thickly set and setiform, and 



^^yi.- 



Fig. 97. Flyiiig-fisli lifted by the wind and cast on llie deck of a 

 vessel, wliicb is sliowii in transverse section. After MoBlus. 



the inner row verrucose and more scattered, like both 

 rows on the other bi-anchia] ai'ches. The gill-openings 

 are large, but close firmly and tightly: the branchio- 

 stegal membranes are entirely separate, but the left 

 closelv covers the right in front. 



Little is yet known of the |)i'(jpagation of the 

 Flying-fishes. Their eggs, like those of the Garpikes, 

 are superficially furnished with filiform appendages. 

 Mathew" supposed that the spawning took place and 

 the eggs wei'e developed in the open sea, since he had 

 found young Flying-fish, less than 3 cm. long, leaping 

 on the Avater. like grasshoppers on land, thousands of 

 miles from the nearest coast. Saunders'', on the other 

 hand, found Flying-fish (he is also silent as to the 

 species) crowding in to deposit their eggs in rocky 

 crevices and holes under the water, on the ("liincha 

 Islands ott' the coast of Peru. This was at the end of 



