38 SUPPLEMENT ON 



all the fish of passage, though some feed on mollusca, at 

 greater depths, are necessitated to deposit their spawn from 

 soundings of at most forty fathoms to the superficial sands 

 and rocks within the tides ; and thus far we may judge the 

 solar rays to penetrate with effect, not only from the quicken- 

 ing of their eggs, but also from the same action upon those 

 of all the other species of fish, and of the pullulations of the 

 subordinate classes of animated beings ; excepting perhaps 

 the zoophytes of some tropical regions, who commence their 

 stony structures under a vertical sun at greater depths, and 

 those pelagian animals whose spawn floats on the surface \ 

 While the migratory tribes deposit upon the zone of sound- 

 ings just mentioned the germs of their own future brood, to 

 be in part devoured by other species, they find in their turn 

 the ova and the fry of those species, and also the already 

 matured new generations of the subordinate classes, to serve 

 for their own subsistence. 



Pelagian fish, though many species are gregarious, are not 

 so clearly migratory as the foregoing. They, as the name 

 imports, are residents in the high seas, and among them the 

 scomberoid family, and particularly the genera istiophorus, 

 xiphias,pelamis,temnodon,and thynnus, certainly frequent the 

 superior strata 2 of the waters, and the two last mentioned, with 



1 It is perhaps necessary to qualify this observation by remarking, that 

 in warmer seas, and particularly in the tropical waters, several of the 

 sedentary species may spawn several fathoms lower down. Yet almost 

 all the tropical percoids deposit their ova about the coral rocks, much 

 nearer the surface, as I have personally ascertained, about Port Royal 

 Keys in Jamaica, and the coral reefs of the Caribbean Sea. C. H. S. 



2 With the exception of the common mackerel, I have found all fish 

 possessed of brilliant colours, and particularly red tints, to be habitually 

 superficial, though very often they reside in the offings, where there is 

 deep water. The seas with corals, which reflect the sun to a great depth, 

 have constantly the greatest variety of species possessed of brilliant 

 colours. C. II. S. 



