288 Dr. Hancock on the Composition of the Fin Rays 



a contrary direction, corresponding, as it were, to the root, or, 

 as Linnaeus has designated it, descending caudex in vegetables. 

 The anterior rays, in some cases, are strong, spinose, and 

 sharp pointed ; they consist of one piece : and a peculiarity in 

 them is a perforation, or around aperture at the base, through 

 which a longitudinal cord or ligament passes — which cord, like 

 the lateral attachment just noticed in the double ones, serves' 

 to confine the bony ray in its place. These spinose single 

 rays are chiefly found in the anterior part of the fins. The 

 same circumstances are found to obtain, more or less, in the fin 

 rays of most of the bony fishes. 



We may easily account, then, far the discrepancies in dif- 

 ferent authors, and the frequent assertion, that the characters 

 derived from the number of rays are found to be variable : for 

 it is plain how the same fish, examined by two different per- 

 sons, or even by the same person at different times, may give 

 results very different in this respect. The most certain way of 

 avoiding such mistakes is also the easiest, and consists of count- 

 ing the rays, without using any violence, taking their numbers 

 as they appear near the base of the fin, or near to the body of 

 the fish : by such precautions the most constant, convenient, 

 and certain characters will be elicited. ^tJiviiJuA 



When the fish are boiled, their muscular attachments Tie- 

 come very slight, and more liable to the deception here noticed ; 

 and it is not unusual for the naturalist to embrace the oppor- 

 tunity at table of examining a fish for such information ; thus, 

 for example, as I have experienced, the five rays (six, Linn.) of ' 

 the ventral fin in a boiled mackerel, being but slightly handled or 

 rubbed between the fingers, will fall into eight or ten. I have 

 only examined the queriman {mugil littoralis) of Guiana, and 

 mackerel, for this elucidation ; and I find the rays of all the fins 

 in the latter to multiply under the fingers in the manner just 

 stated (i. e. in a boiled fish), with exception of the anterior 

 dorsal fin, which consists of sharp pointed spines, with per- 

 forated apophyses *. 



I am doubtful as to the method observed by Linnaeus,- in 



* I have, since the above was written, examined several other fishes, gadi and 

 pleuronectes, as the whiting, haddock and cod, sole and flounder 5 and 1 find the 

 same circumstances to prevail in all of them : it may, therefore, most probably, be 

 considered as the general structure. 



