364 ON THE ANATOMY OF THE STURGEON. 
may serve to direct the attention of those who have more 
frequent opportunities of observing the habits of fishes than 
my other engagements allow me. 
Most of the objects represented in the engraving, Plate 
IV., have been explained already in the course of the fore- 
going account. Fig. 1. represents the cesophagus and sto- 
mach, the former widi its pap'ill(B^ the latter with its cur- 
vatures ; and a more complete view of the direction of these 
curvatures is given in Fig. 5. Fig. 2. exhibits the pan- 
creatoid organ, the pylorus^ and the duodenum^ with the 
reticular structure of its inner membrane. Fig. 3. shews 
the intestine with the spiral valve ; A A, the axis or central 
column ; r r 7*, the reticular cells on its right side ; and III, 
the smooth ones on its left. Fig. 4. is the posterior mar- 
gin of the orifice into the swimming bladder. And in 
Fig. 6. are seen the four openings, the anus (a) and ^ire- 
thra (ti), on the mesial plane, and the lateral peritoneal ori- 
fices (o d) on each side. 
