REPORT OF COMMISSIONERS OF INLAND FISHERIES. 169 



2. A stream from the middle pyloric canal. This contains the 

 rejected material from the lateral pouch and is probably formed 

 almost wholly by that material. Bristles from five to fifteen mm. 

 long are the only large objects which we have found in the pyloric 

 sac. These pass through the lower chamber and the middle canal. 

 It is possible, however, that the relaxation of the constrictor muscles 

 may allow relatively large objects to pass through the sac. 



3. A stream from the lower canal. This contains the greater 

 part of the material brought into the pyloric sac by the upper cardiac 

 canal. In addition, it doubtless contains a portion of the fluids 

 which enter the pyloric sac through the upper and lower chamber 

 and which gravitate into the canal. The coarser particles are re- 

 moved from the lower canal by the sieve of the lateral pouch and are 

 carried into the middle canal. This lower stream of food enters the 

 lobes of the liver and is there, in part at least, digested and absorbed. 



The view of the function of the stomach which is here presented 

 is in radical disagreement with the common explanation which, 

 without accounting for the final disposition of particles caught by 

 the bristles of the pyloric sac, regards the sac merely as a filter. It is 

 in slight disagreement with the admirable work of Jordan who failed 

 to discover the cardiac canals and so was led to believe that the food 

 stream entered the lateral pouches from the middle canal. 



The Stomach of Larval Lobsters. 



The stomach of lobsters of the fourth stage is like that of the adult. 

 The less strongly calcified plates of the adult, for example, the anterior 

 lateral, the upper intermediate, and lower intermediate cardiac bars, 

 and the anterior dorso-lateral cardiac plate, are not recognizable in 

 the stomachs of the earlier stages which have the adult form. The 

 stomachs of lobsters of the first, second, and thirci stages (the larval 

 stages) have the same general form and musculature (extrinsic and 

 intrinsic) as the adult stomach. These stages are unlike the adult in 

 the following important points : 



