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COMMON TERN. 



-f- Sterna Hirundo, Linn. 

 PLATE CCCCXXXIIL— Adult Male. 



Although the Prince of Musignano has thought that the bird named the 

 Common Tern in America, differs from that bearing the same name in 

 Europe, and has in consequence changed its appellation to that of Wilson's 

 Tern, I am of opinion that no difference exists between the Common Terns 

 of the two Continents. The cry of both is besides precisely similar, so that 

 with me there is no doubt whatever as to their identity. Experience has 

 shewn me that the markings or white spots on the primary quills of Gulls, 

 at one time assumed as a criterion by which species might be distinguished, 

 cannot in the least be depended on, varying, as they always do, in individuals 

 of the same species, at almost each successive moult. Then why, reader, 

 should not Terns exhibit analogous changes? The fact is, they do so; and 

 it is almost impossible, on closely inspecting a dozen or more specimens pro- 

 cured at the same period, in either country, to find two individuals exactly 

 corresponding in every particular. Some have the bill almost entirely black, 

 while others have it more or less red and black, and tipped with yellow. 

 The length of the tail-feathers, that of the tarsus, and the size of the inter- 

 digital membranes, are all found to differ in some degree, if minutely com- 

 pared. If species are to be founded on such slight differences, an ample 

 field is open to those who are ambitious of being discoverers. At all events, 

 I cannot help remarking here, that it seems to me improper to impose new 

 names on objects, until it is proved by undeniable facts that they present 

 permanent differences. 



I have observed this species along the Atlantic coast of North America, 

 from Galveston Island in Texas to the Straits of Belle Isle on the coast of 

 Labrador, both in spring and in early autumn. But when on the islands in 

 Galveston Bay, in the month of April, I saw only a few arriving there from 

 the west; whereas, in the beginning of May great numbers arrived there 

 from the east, settled at once, and commenced breeding. I felt convinced 

 that the numbers which came from the direction of the Floridas were much 

 greater than those which arrived from the westward, and judged it probable 

 that vast numbers had at the same time left the Peninsula on their way 



Vol. VII. 14 



