FISHES. 453 



to mankind," says Bacon, " arise from tlie changes and altera- 

 tions of the atmosphere ; but fishes reside in an element little 

 subject to change ; theirs is a uniform existence ; their move- 

 ments are without effort, and their life without labour. Their 

 bones also, which are united by cartilages, admit of indefinite 

 extension ; and the different sizes of animals of the same kind, 

 among fishes, is very various. They still keep growing ; their 

 bodies, instead of suffering the rigidity of age, which is the cause 

 of natural decay in land animals, still continue increasing with 

 fresh supplies; and as the body grows, the conduits of life furnish 

 their stores in greater abundance. How long a fish, that seems to 

 have scarcely any bounds put to its growth, continues to live, is 

 not ascertained; perhaps the life of a man would not be long 

 e;iough to measure that cf the smallest." 



There have been two methods devised for determining the age 

 of fishes which are more ingenious than certain ; the one is by the 

 <;irclesof the scales, the other by the transverse section of the back- 

 bone. The first method is this : When a fish's scale is examined 

 through a microscope, it will be found to consist of a number of 

 circles, one circle witliin another, in some measure resembling 

 those which appear upon the transverse section of a tree, and 

 supposed to ofl'er the same information. For as in trees we can 

 tell their age by the number of their circles, so in fishes we can 

 tell theirs by the number of circles in every scale, reckoning one 

 ring for every year of the animal's existence. By this method, 

 Mr Buffon found a carp, whose scales he examined, to be not 

 less than a hundred years old ; a thing almost incredible, had we 

 not several accounts in other authors which tend to confirm the 

 discovery. Gesner brings us an instance of one of the same age •, 

 and Albertus of one more than double that period. 



Tlie age of the skate and the ray, that want scales, may be 

 known by the other method ; which is, by separating the joints 

 of the back-bone, and then minutely observing the number of 

 rings, which the surface where it has joined exhibits. By this 

 the fish's age is said to be known ; and perhaps with as much 

 certainty as in the former instance. 



But how unsatisfactory soever these marks may be, we hi:vo 

 no reason to donht the great age of some fishes. Thos-e that 

 have ponds, often know the oldest by tlieir superior size. But 

 the longevity of these Kulmals is nothing when compared to thcii 



