612 



EIDER DUCK. 



is 1 inch, it then enlarges so as to form what might be considered as a 

 kind of crop, 1 inch 7 twelfths in width ; after this it continues of the uni- 

 form diameter of 1 inch, but in the proventriculus, Fig. 1, h c, enlarges to 

 \^ inch. Its muscular walls are very thick, and the external fibres con- 

 Fig. 1. 



