98 



RED-BREASTED MERGANSER. 



among the Mammalia. This kind of ear forms the extreme contrast 

 to that of the nocturnal rapacious land birds. In the Ducks and Geese 

 it is also small, but much superior in size to that of the Mergansers. 

 The oesophagus, ahcd, is twelve inches long, its diameter at the upper 

 part 1^ inch, farther down 1 inch and 7 twelfths, within the thorax 1 

 inch 4 twelfths, at the proventriculus 1^ inch. It is thus extremely 



Fig. 1. 



'e 



wide, like that of other diving piscivorous 

 birds. The stomach, d e, is roundish, of 

 moderate size, 1 inch 8 twelfths in length, 

 1 inch 11 twelfths in breadth. Its lateral 

 muscles are of moderate thickness, its epi- 

 thelium tough, with two grinding surfaces 

 of a rovmdish form, and thus resembling that 

 of Ducks. The contents of the stomach 

 are remains of fishes and a great quantity of 

 gravel. The inner surface of the oesophagus 

 is very smooth when extended, plicate when 

 contracted, with longitudinal series of mu- 

 cous crypts with wide apertures, which be- 

 come more numerous and close toward the 

 proventriculus. The glandules of the latter 

 organ are irregularly distributed, forming a 

 belt 1^ inch in breadth. They are cylindri- 



Fig. 2. 



'9 



