and the Anatomy of Fishes, 289 



numbering the rays of the caudal fin ; in most of his Sparii, for 

 instance, we find he has reckoned about 17 or 18, and at most 

 22 rays, which is in his Sparus veryatus. Now this species 

 has ] 8 long rays, besides the shorter ones above and below, 

 which amount to twelve more, making 30 in all ; and this I 

 find to be constant, from examination of several individuals : 

 they are not all visible, however, without dissection, or till, by 

 boihng or otherwise, they are denuded. It would seem from 

 this, that he neglected to enumerate these shorter rays in the 

 caudal fin ; but we can hardly suppose he would purposely omit 

 them, because some of them are as long, and quite as obvious, 

 as the middle ones''*'. 



On recurring to those before mentioned, I found that every 

 one of these radii are twin or double — even the very outermost 

 or shortest, which are so small as to require a lens to observe 

 them. Being composed of jointed half cylinders, applied in 

 such close contact as to appear quite entire, and forming tubes 

 which are occupied by a gelatinous^substance, or albumen per- 

 haps, as it seems to coagulate or harden with heat — these bones 

 branch off about their middle, with two radii, and are thence 

 subdivided into eight. When the investing membrane is re- 

 moved, and the gluten about them dissolved by boiling or ma- 

 ceration, the^two pieces will separate spontaneously in drying. 



No other structure could at once afford such strength, light- 

 ness, and elasticity, as that which we thus observe in the fins of 

 fishes. We see that all those fins which require a power of 

 strong lateral exertion, are chiefly composed, as above noticed, 

 of two semicylindrical portions, laid in contact, admitting of a 

 small sliding motion. They stand separate, and somewhat 

 distinct at the base (especially in the caudal fin), which gives 

 them a degree of firmness or a bracing power ; and a projec- 

 tion of each at the base gives insertion or attachment to strong 

 lateral tendons, which serve to pull them to either side. To 

 augment their elasticity and easy motion, they abound with 

 sl^ort joints, especially towards their extremities : finally, to 



,* We must consider, however, that many, or doubtless the far greater part of the 

 descriptions of Linne are derived from various other authors, in which he found 

 the species and genera confounded, and only doubts and obscurity prevailing. 

 His system, therefore, should be regarded as only an approximation, or rather as 

 the foundation of a method (and that the best of all, so far as it goes) for reduc- 

 ing this chaos to some order. The misfortune is, it has been considered as too 

 great an advance towards perfection* 



