278 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



Below the pylorus the iiitestiue is expanded for tin iuch and a quarter 

 of its length. It is into the inferior wall of this basin that the largest, 

 longest, and the greatest number of these appendages enter. 



The c(Bca vary in length, by actual uieasurenient, from an inch to 

 three inches and a half; and in circumference, from tliat of a small probe 

 to that of a number si-x catheter. When the fish is in good condition, 

 they are sei)arated i'rom each other, and supported by delicate layers of 

 fat; the cellular tissue of which is abundantly supplied with vessels, that 

 expend themselves on the walls of the C(Bca. The blind extremities of 

 the sacculi gravitate treeiy in the abdominal cavity. 



Such, in part, is pi rapid anatomical sketch of the organs of digestion. 

 What is the food of the fish? and what are the functions of the cffica? 



As the shad of the Western Atlantic makes its appearance first oft' the 

 coast of Georgia, it occurred to me that could specimens, /m/z-nni from 

 the sea, be obtained from this locality immediately after the a})pearance 

 of the fish, that an opportunity would be offered of discovering from the 

 contents of the stomach jnore in relation to its habits than was known. 



On the 2d of February of the current 3'ear, two shad, which were for- 

 tunately ijrocuied from Savannah, Ga., were examined at my office in 

 Mobile. 



The stomach of the first contained nothing except a small quantity of 

 brownish mucus, which others liave described. 



But 1 was astonished to find the coeca greatly elongated and distended. 

 They were of a tiesh color — evidently due to their contents, viz : a homo- 

 geneous-looking fluid, which, when squeezed through the coecal orifices 

 into the intestinal canal, was found not to differ materially, under the 

 naked eye, from the brownish mucus alluded to above. To my mind the 

 functions of the coeca were api)arent. 



The gizzard-stomach of the second specimen, in addition to the brown- 

 ish mucus, contained a minute quaiitity of solid matter. This was im- 

 mediately mounted on a slide and subjected to a lens of low i)Ower 

 suitable for examining vegetable tissue entire. 



I was amazed at the beauty and perfection of the objects displayed — 

 minute cylindrical stalUs, and differently shaj)ed and colored fragments 

 of alga?, gemmed with the pearly calcareous shields of infusoria! Many 

 of the shells, hi^ving altogether escaped the effects of the action of the 

 stomach, preserved their integrit}' — bi convex loricae predominating. 



A Bailey would know and name them at a glance. 



They are to be seen of all sizes, from the fully formed disc to that 

 presenting under the same power a mere i)oint. 



An algologist might readily determine the species to which the fuci 

 belong. 



The question relative to the food oi Alosn prccstabiUs is answered. 



Shad feed and fatten on marine fuci, and on the microscopic organisms 

 that are parasitically attached. Both are necessary to the economy of 

 the fish. How beautiful the adaptation! The succulent vegetable mat- 



