COMMON TERN. 75 
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 northward. 
Should other travellers observe the same or similar phenomena at the 
season mentioned, it will be proved that this species does not extend 
its autumnal migration so far as several others, which I observed ar- 
riving at Galveston Island from the south-west, for example, the Least 
Tern, Sterna minuta, the Cayenne 'Tern, St. cayana, and the Black 
Tern, St. nigra. 
The Common Tern commences breeding on the coast of our Middle 
Districts about the 5th of May. On my voyage to Labrador, I found 
its eggs on the islands in the Gulf of St Lawrence, and especially on 
the Magdalene Islands, which I visited on the 11th of that month. 
On the 18th I saw them in great abundance in the neighbourhood of 
American Harbour, on the coast of Labrador, where thousands of 
Terns were plunging headlong after shrimps all round us. In that 
country, their eggs were deposited among the short grass, and the 
places which they occupied were but slightly scratched; whereas on 
the Magdalene Islands, where they breed on sandy ridges, slight hol- 
lows were scooped out, as is generally the case along the eastern coast 
of the United States. Their sojourn in Labrador is of short dura- 
tion ; and when we were at Newfoundland, on the 14th of August, 
multitudes were already passing southward. At the same period con- 
siderable numbers pass by an inland route from the Canadas, and all 
our great lakes, travelling along the Ohio and Mississippi. While re- 
siding at Henderson, and afterwards at Cincinnati, I had ample op- 
portunities of watching their movements in the month of September. 
And yet, you will think it strange, that, during their vernal migration, 
I never saw one ascend any of these rivers or the streams connected 
with them. Perhaps the inferior temperature of the waters, compared 
with those of the ocean, in the early spring months, may induce them 
to abandon their route at that season. In autumn, on the contrary, 
when these rivers are heated and reduced in size, the Terns may find 
in them an abundant supply of the fry of various fishes. It would 
thus appear, being corroborated by other observations which I have 
made relative to migration, that species whose range is extensive, are 
determined in their movements by a genial temperature and an abun- 
dant supply of food. 
