Sir Everard Home’s account, &c. 333 
the materials of which they are composed, and gives it de- 
cidedly as his own opinion, that, whatever it is, it is brought up 
from the stomach, and requires at times so great an effort, 
as to bring up blood, the stain of which is seen on the nest. 
This account of Sir Stamford Raffles, in the correctness of 
whose observation I have the greatest confidence, led me to 
investigate this subject, and to ascertain by examination whe- 
ther this particular swallow has any glands that are peculiar 
to its oesophagus, or stomach, enabling it to secrete a mucus 
similar in its nature to the substance of which the nest is com- 
posed. I at the same time requested my friend, Professor 
Brande, to analyze one of the nests, and to inform me of its 
composition. In examining the gastric glands of the Java 
swallow, even with the assistance of a common magnifying 
glass, I saw an obvious difference between the appearance of 
the orifices by which the secretion is poured into the gizzard, 
and of those of other birds, but, as I had never examined those 
glands in the common swallow* which migrates to this coun- 
try, it became necessary, before I proceeded farther in the 
enquiry, to ascertain whether in all the swallow tribe there 
were similar structures. In the present season this oppor- 
tunity has be'en afforded me, and I find that in the common 
swallow, both male and female, the orifices of the gastric 
glands differ in nothing from those of birds in general, but 
that the peculiar structure which I am about to describe is 
confined to the Java swallow. This bird, Sir Stamford Raf- 
fles informs me, does not migrate, but remains all the year 
an inhabitant of the caverns in that island. Some of the most 
extensive caves in which they reside, are forty miles from 
either sea. Those swallows that build their nests near the 
