37 



the Lnter-spinous processes, and corresponding dorsal fin, from any immediate 

 connection with the spinous processes of the skeleton, explaining the 

 almost complete disappearance of the fin, in the recently caught specimen. 

 The abdominal plate or process will be observed to support the ribs, as 

 previously remarked ; and it is necessary, particularly, to refer to this fact, as, 

 in describing the caudal division of the spine, it will be again alluded to. 



About the eightieth vertebra, the canal for the blood-vessels begins to be 

 formed, and here an additional system of processes is found. The abdominal 

 processes close upon each other, still continuing to support delicate, hair-like, 

 ribs, while a series of cartilaginous processes gradually appear on the lateral 

 surfaces of the bodies of the vertebrae, and continue to the extremity of the 

 spine. There are two of these processes on each side, evidently arising from 

 the vertebrae in the fish being composed of two elementary parts, divided 

 transversely in the middle, like an hour-glass ; and the resemblance is 

 rendered perfect by the communication being free, a fine wire passing readily 

 through. The fact of a vertebra being, at an early period of the progressive 

 development of the skeleton, composed of the elements of two vertebrae (and 

 this can scarcely be doubted), would, if the development was arrested, give 

 double the number of vertebrae, or 420 instead of 210. 



Had Sir Chaides Bell selected, for his Bridgewater Treatise, a vertebra, 

 instead of the hand, as illustrating the " Unity in the Type of Organization," 

 he would undoubtedly have experienced much greater difficulty in producing a 

 very popular volume, for which he received the very handsome sum of £1000. 

 The treatise, it would appear, gave offence to no one, and, yet, it was a very 

 bold proceeding to trace analogy between the boasted hand of man, the club- 

 shaped pectoral extremity of the elephant, the bat's flying arm ; and the fin of 

 a fish. 



THE RIBS, 



I have remarked, are exceedingly delicate, and more resemble numerous, 

 hair -like, semi-ossified, prolongations, giving attachment to the inter- 

 costal muscles. In many species of fishes, as, for example, in the herring, 

 these same ossified processes are very numerous ; and, I think, by many 

 anatomists, are considered ossified tendons of the muscles, not found 

 in any other animals but fishes. In birds, we observe a tendency in tendinous 

 prolongations of the muscles to become osseous, but these ossified tendons in 

 birds, cannot be considered in any way analogous to the hair-like processes I 

 now allude to. 



THE LOCOMOTIVE ORGANS 



in the shape of the pectoral and ventral fins, are not particularly well 

 repi-esented. No vestige of ventrals can be observed, and the pectorals are 

 exceedingly small. The Ophisurus finds his food amongst the mud and stones, 

 in the estuaries of rivers ; and with the assistance of the cutis-muscle, already 

 alluded to, will be able to make considerable way over the mud. I may 

 remark, that the Murcena, or common eel, does not possess this abdominal 

 cutis-muscle, but a thin layer of muscular fibres can be observed on each side 

 of the caudal extremity, acting in a lateral movement of the tail, and facilitating 

 the eel in progressing through the water. 



THE MUSCULAR SYSTEM, 



it will be observed, from the annexed table of weights, is greatly developed, 

 and altogether connected with the spinal column — the pectoral fins being 

 merely rudimentary, and the ventrals entirely wanting. A careful anatomical 

 dissection would, no doubt, show that the anatomy of the human subject, was 

 not essentially deviated from. It may suffice, howevei', to state, that it 



