PEAR, NUPTIAL SEASON, AND INHERITED INSTINCT. ' ' lxxvii 



beating the water with their wings, so as to scare, the fish, when they fall an 

 easy prey. Sars has observed how pollack succeed in alarming a school of 

 sand-eels, Ammodytes (vol. i, p. 329), and driving them towards the surface, 

 when they become a prey to gulls from, above .and these fish from below. 

 Similarly, porpoises have been observed to swim round masses of gregarious 

 fishes, and when they were alarmed, feasting on them with impunity : the 

 gar-fish, Belone, of the British seas (vol. ii, p. 146) may then be observed to 

 mount to the surface and crowd on each other as they press forward. When 

 still more closely pursued, they spring out of the water to the height of 

 several feet, leaping over one another in singular confusion, and again sink 

 beneath. The flying fish, Exoccetus, similarly springs out of the water to 

 escape its rapacious pursuers (vol. ii, p. 155.) Members of the herring 

 family, Glupeidce, would seem to be those in which more predacious forms 

 appear to induce terror. Thus the gar-pike, in the eastern seas, may 

 frequently be seen pursuing anchovies along the surface of the water. 

 Every angler is aware of the natural timidity of fishes, and keepers know 

 how easily .poachers are able to deter salmon from ascending fish-passes. 



During the nuptial season, teleostean fishes (page lvii) have more 

 resplendent tints than at any other period of the year, and this may be 

 for the purpose of mutual attraction, as seen in the salmon, stickleback, 

 &c. While in the United States a male of the John Darters, Etheostoma 

 blennoides, kept in an aquarium, underwent, almost in an instant, an entire 

 change of pattern in the colours on its body, upon the introduction of a 

 female fish of the same species. Even after two weeks the novelty had not 

 worn off, though its body-colours varied much from hour to hour, but had 

 not reverted to its original dress. 



Inherited instinct is a subject in fishes worth attention. Due to it the 

 young of many sorts return from the sea to the localities where they were 

 originally reared, and in their turn produce offspring inheriting the same 

 tendency. Similarly, we may perceive inherited fear; a young fish just 

 hatched will hide itself from the gaze of other animals. 



Some fishes have the curious instinct of obtaining assistance from other 

 forms in their search after food or their migrations from place to place; this 

 latter being done in order to profit by the greater powers of locomotion in 

 their host, from whose body, however, they draw no sustenance; but are 

 commensals, merely partaking of such food as Comes within their reach. 

 Among these latter we have the sucking-fish, Echenels, as an occasional 

 wanderer to our shores (vol. i, p. 10G). The Fierasfer (vol. i, p. 328), 

 which is another rare visitant off our coast, is often known to seek its 

 fortune inside the sea-cucumber or Ilolothnria, upon which it may be said 

 ■ to be a "free messmate." It works its way into its host tail foremost, 

 while many of the young of our commoner forms' seek refuge in Medusce 



