2 SECRETS OF ANIMAL LIFE 
selves in all probability in a region which they 
never before visited. Furthermore, as Bird Key is 
the last piece of land between the coast of Florida 
and the coast of Texas, the birds can be sent out to 
sea for hundreds of miles beyond sight of all land- 
marks. Between Bird Key and Galveston, for 
instance, there is open water for 855 statute miles, 
obviously a fine expanse for homing experiments. 
The technique of the experiments is as follows: 
A bold, vigorous tern is caught, it is marked char- 
acteristically with oil-paint on the head and neck; 
two tags (small and large, but otherwise duplicate) 
are prepared, recording the date, the place, and the 
kind of marking; the small tag is tied round the 
bird’s neck; the large tag is fixed to a foot-long 
stake pushed down into the sand near the nest if 
the bird is a Sooty or tied to a convenient twig if 
the bird is a Noddy; the bird is put into a large 
hooded cage and transported to a distance on 
board ship; it is kept in good health with minnows 
from the refrigerator; it is liberated at a chosen 
point; and then its return to the nest is watched 
for. The most important general result is that 
these terns are able to return from Galveston, 
more than 800 miles away, over a body of water 
which apparently does not offer any basis for con- 
trolling flight direction. Some returned in about 
six days, some took nearly twelve, some did not 
return at all. Many of the return journeys from 
distances greater than 500 miles did not require 
more than three to five days, but sometimes as 
