FISHERY BULLETIN: VOL. 71, NO, 2 



Figure 17. — Epithelium in the gall- 

 bladder of cunner showing rodlet 

 cells (r), vacuoles (v), and digitiform 

 processes (d) (X 1,000). n, nucleus 

 of rodlet cell: Sm, subniucosa. 



.^^ 





Sm 





-•tMO»» 



are in direct contact with the lumen. The 

 cytoplasm of the rodlet cells (Figure 17) con- 

 sists of many granules with a threadlike struc- 

 ture extending from each granule to the distal 

 end of the cell. These granules are acidophilic 

 and stained deeply with PAS technique. A 

 large nucleus is near the base of the cell. 

 Various developmental stages of the rodlet 

 cells can be observed in some of the bile duct 

 preparations. 



SUBMUCOSA.— The submucosa, which 

 forms the core of the mucosal folds of the intes- 

 tine, is a single homogeneous layer of fibrous 

 connective tissue between the epithelium and 



muscularis (Figure 11). The stratum com- 

 pactum, a thin layer of dense connective tissue, 

 can be identified just beneath the mucosa (Fig- 

 ure 15). The collagenous fibers in the sub- 

 mucosa are more dense at the posterior por- 

 tions of the intestine and rectum. Several cell 

 types are scattered in the collagenous tissue. 

 The most abundant cells are fibroblast of dif- 

 ferent stages. The young fibroblast has an ovid 

 nucleus and basophilic astral cytoplasm (Figure 

 18). The fibrocytes (mature fibroblasts) are 

 most easily seen in the submucosa of the top 

 of the folds. It is very difficult to see any 

 cytoplasm in these fusiform cells. The nuclei 

 of fibrocyte is elongate or oval in shape with a 



Figure 18. — The submucosa of the 

 intestine of cunner ( X 1,000). ft, 

 fibroblast; fc, fibrocyte: g, granulo- 

 cyte; 1, lymphocytelike cell; ly, lym- 

 phocyte; n, nucleus of granulocyte. 



576 



