To appreciate this, it is sufficient to enumerate the birds without the critical muscle: Passeriformes and Coraciiformes, without exception; Ardeae and Podiceps; lastly various genera of storks, pigeons, parrots, petrels and auks.
In humming-birds and petrels the trachea is partly divided by a vertical, longitudinal, cartilaginous septum.
A similar rotation and dislocation occurs in various petrels, in correlation with the indigestible sepia-bills, &c., which these birds swallow in great quantities.
Tubinares, petrels and albatrosses.
27) are steps which, though indicated by Merrem, are here for the first time clearly laid down; and the separation of the gulls from the petrels (No.