FISHES. 27 



the spinal column. The productions of peritoneum by which it is 

 connected with the lamina that surrounds the intestine, are mostly 

 filaments or narrow bands remote from each other, and only rarely 

 form a mesentery. In these productions, and also in the free folds 

 of peritoneum, which may be compared with the onmitum, there 

 often lies a larger or smaller quantity of very white and soft fat. 



The blind appendages {cceca, ajypendices 2^y^oricce) deserve a 

 special notice, which are attached to the intestinal canal in the 

 neighbourhood of the pylorus, and in which a tenacious, slimy fluid 

 is secreted. They are wanting in the Plagiostomes and Gyclostomes, 

 in the Plectognathi and Lophohranchii, as also in some common bony 

 fishes, as in the pike and in the carps (the genus Cyj^rinus L.). 

 When present they differ much in form, size, and number. Poly- 

 2)terus and Ammodytes tohianus have only one such appendage, 

 Lopliius piscatorius has two, the perch three, in Trigla five or 

 more are counted, nine or ten in Scicena aquila, and they are still 

 more numerous in the genus Gadus, in the herrings and salmons. 

 When they are numerous they sometimes unite at their insertion in 

 the intestinal canal to form common ducts, so that there are fewer 

 openings into the intestine than blind appendages. Sometimes they 

 are collected into bundles and connected by cellular tissue, as in 

 Xtphms gladius^, and in the sturgeons, where they form a gland- 

 like body with a single efferent duct^ Accordingly these append- 

 ages have been usually regarded as supplying the office of a pan- 

 creas, which in the sharks and rays presents itself in the ordinary 

 form. In the pike the jyanoreas^ as a long whitish-yellow gland, 

 lies along the left side of the stomach, connected with the liver by 

 many short vessels, and covered by it. In the pike the ^^awcreas, 

 as a longitudinal whitish-yellow gland, lies along the left side of 

 the stomach, connected with the liver by many short vessels, and 

 covered by it. Also in the eel, Murcena anguilla, a pancreas is 

 found, which, as an elongated reddish-white mass terminating in a 

 point backwards, lies upon the intestinal canal, and delivers its 



1 EosENTHAL AbkancUungen aus clem Gebiete der Anatomic, Physiol, und Pathologie. 

 Berlin, 1824, 8vo, s. 79. The branches of these bundles unite here to form two stems, 

 which are inserted close to the pylorus. 



2 Observationes anatomicce Collegii privati Amstelodamensis. Amstelodami, 1673, 

 i2mo, pp. 17—24, Tab. III.; MoNEO Struct, and Physiol, of Fishes. Edinb. 1785, fol. 



PI. IX. 



