STERNA OF THE PENGUINS. 379 



the \vay in which the head of the clavicle is united to 

 that of the scapular, so as to bend that bone more 

 firmly against the ribs near the inflexible part of the 

 spine, when the pressure of the water tends to bend 

 the clavicle itself toward the angle of the sternal 

 keel, are all well worthy of close observation : the 

 more so that the natural action of the bird in the 

 water cannot be so easily seen as that of a land bird 

 in the air. Even the point of articulation of the 

 wing is worthy of notice, as having the line of its 

 principal action more in the direction of the general 

 axis of the body than that of wings which are used 

 exclusively in flying. Taken altogether, the divers 

 afford one of the finest and most instructive instances 

 of mechanical perfection which is to be met with in 

 the whole feathered race. Not that their structure 

 is better adapted to their habits than that of any 

 other tribe, for in this all birds, and indeed all animals, 

 may be said to be alike ; but their action is particu- 

 larly energetic ; and the energetic action strikes us 

 with admiration, while in the case of that which is 

 less conspicuous we must examine before we can 

 admire. Those striking cases are of course the ones 

 which it is best to present to those entering upon the 

 study ; whether the object be to produce love for the 

 productions of nature, or the inseparable adjunct of 

 that love when grounded aright veneration for 

 nature's Almighty Author. 



3. Sterna of the penguins. In these birds the 

 wings, which in the divers, and also in some of the 

 intermediate genera of auks, are capable of tolera- 

 bly rapid and prolonged flight, so that the birds can 

 not only range over the surfaces of the bays and 

 landward parts of the sea, but migrate from one lati- 

 tude to another as circumstances may require, are 



