Mr. Home on the different Structures and Situations^ &c. 395 
and rounded off at the other ; they are placed on the outside 
of the membrane which lines the cardiac cavity, they lie 
parallel to one another, and nearly at right angles to the 
membrane through which they open, the closed end being 
slightly turned upwards, so as to make the orifice the most 
depending part. In the golden eagle, (the Falco Chrysaetos 
Linn.) and the sea eagle, (Falco ossifragus), they form, 
altogether, a broad compact belt: but in the hawk, (Falco 
Nisus) this belt is slightly divided into four distinct portions; 
immediately below these glands the cavity becomes wider, 
and is inclosed in a digastric muscle of weak power, with a 
flat tendon on each side. The internal surface of this cavity, 
which is the gizzard, is soft and vascular.* 
In all birds that live on animal food,, the solvent glands ap- 
pear to have a similar structure to that which has been just 
described, only differing in size and situation. The following 
are the most material differences which I have met with re- 
specting their situation. 
In the Soland goose, (Pelecanus bassanus,} these glands 
are rather larger than in the eagle, but are placed in the 
dilated part of the cavity of the gizzard, forming a complete 
belt of great breadth, consequently are extremely numerous. 
Their situation and appearance is shewn in the annexed 
drawing. 
In the heron, (Ardea cinerea), the solvent glands are in 
the same situation as in the Soland goose; they are thinly 
scattered, and do not form E a complete belt, being more 
numerous on the anterior and posterior surfaces. A ball of 
• An engraving of this appearance is given in the Philosophical Transactions for 
the year 1807, p. 178, pi, xii. 
