360 KAilAKICHI KISHKOÜYE: 



coimective tissue, and the whole roass of the pyloric coeca is again enclosed and 

 conneeißd comj)actlT by a common membrane, the peritoneum. In pyloric tubu- 

 les wc find a viscous, milky fluid ; and sometimes half digested particles of food 

 as well, when the stomach is glutted. Mi'. Tu Tokoya examined for me the 

 nature of enzymes in the pyloric coeca of Neotliumms macropterus, and obtained 

 the result that amylase and protease are präsent, but he could not detect the 

 presence of hj)ase. This result confirms other author's' results of investigations, 

 and points out that the chief function of the pyloric coeca is digestive. In this 

 inquiry glandular' portion only was used, so that thei'e was Httle fear of mixing 

 of gastric juice. 



In the Cybiidae the number of pyloric tubules is few (2-6), and small 

 one of them is often found on the anterior concave side. The coecal portion 

 is sparingly branched. In the Plecostei the numl^er of pyloric tubules is a Uttlo 

 more numerous (5-10), and their short tei'minal branches carry tufts of simple 

 coeca. Two or three small tubules are found on the concave side of the pyloi'us 

 in the Katsuwonidae. In the TTiuunidae the size of coeca is not uniform, those 

 near the distal end of the longest pyloric tubule being larger than others. Tlie 

 tubule next to the pylorous is longest, and succeeding ones rather suddenly de- 

 crease iu length. These tubules are genei-aUy disposed at the postei'ior side iu 

 a line along the entire length. Theii' orifices to the duodenum ai'e variable iu 

 size and form, Ijeing roimd, oblong, or sometimes sht-like. 



Intestine. The duodenmn is trausfeiTed to the small intestine at the spot 

 where the alimentaa'y canal is bent backwai'd, i. e. at the junction of the 

 ascending and descending x'ax'ts of the alimentai'y canal. The length of the 

 small intestine is very variable. It is shoi't and straight iu Ch'ammakn-cynus 

 and Katsuwonidae, and long and more or less folded in the Scombridae, Cybiidae 

 (except Grammcdorcynits) and Thunnidae. In BastreUiger, some sj^xicies of 

 Cyhium, and fishes of the Thunnidae the intestine is comparatively and nearly 

 uniformly slender; but in these cases the intestine is always much elongated. 

 The intestinal tract is a httle more slender tliau the duodenum. In the Eatsu- 

 wonidae the small intestine is very shoi't, being nearly- equal in length with 

 that of the abdominal cavity. But the intestine is often thicker than the rec- 

 tum, and many weak longitudinal folds are found in it. Sometimes the rectum 

 is tliickei' tlmu the small intestme. In this familv the intestine is nearly equal . 



