184* Sir Everard Home’s observations 
the object of this paper to communicate to the Society, we 
are indebted to Mr. Bauer, who has given the most patient 
and laborious attention to the examination of these parts, mag- 
nified in different ways, and has faithfully represented them 
as they appeared to his view. 
From Mr. Bauer’s examinations, we find that the human 
urethra is made up of two parts, an internal membrane, and 
an external muscular covering. 
The internal membrane is exceedingly thin, and no fibres 
are met with that can give it a power of contraction. When 
it is put on the stretch in a transverse direction, the circum- 
ference of the canal is no ways encreased ; but when 
stretched longitudinally, a small degree of elongation is 
produced. 
When a transverse section of the urethra is made while in 
a collapsed state, the internal membrane is found thrown into 
folds pressed together by the surrounding parts. This ap- 
pearance is shown in the most satisfactory manner in the 
annexed Plates. 
On the surface of the internal membrane, over which the 
urine passes, there are numberless small projections, or 
papillae, the orifices of glands. The surface is covered with 
small blood-vessels, and the lacunae leading to the deeper 
seated glands, are very numerous. These parts are beauti- 
fully represented in Plate XXI. Fig. 4, in a small portion of 
the lining of the urethra, near the external orifice, minutely 
injected, magnified ten times in diameter. 
The muscular covering by which the membrane is sur- 
rounded, or enclosed, is made up of fasciculi of very short 
fibres, which appear to be interwoven together, and to be. 
