MUCOUS SEAT OF THE DIGESTIVE CANAL. 459 
they always remain there, at least I have seen them plainly 
enough in very old horses. 
They are more numerous and more easily seen in entire horses 
than in geldings or mares : in coarsely-formed horses, however, 
and horses of heavy draught, there is very little difference in 
this respect. 
Chronic alterations in the mucous coat of the intestines, the 
presence of worms, local engorgements, sometimes render the 
hairs more apparent. The length of the hairs is variable. In 
the small intestine, near the pylorus, I have found them six lines 
in length ; but their ordinary length does not exceed a line and 
a half or two lines, and they are sometimes so small as to be al- 
most imperceptible. On the same place, or within the space of 
a square inch, there is sometimes a very great difference, both in 
their length and their bulk. The longest are those which are 
found in the groups of mucous follicles. In general, they are 
longer at the pylorus than in the colon, and in that than in the 
csecum. 
They are differently coloured, according to the colour of the 
animal, and are generally as nearly as possible of the same hue 
as his coat. I have not had opportunity to remark whether, in 
piebald horses, there are patches of different colours in the 
intestinal canal. I purpose to continue my investigations in 
every point that can be interesting with reference to natural his- 
tory. In the portion which is actually adherent to the mucous 
membrane, they are colourless ; it is only at some little distance 
from the membrane that they assume their various hues. 
Their size is as variable as their length. I have met with 
some near the pylorus which were as large as a hair from the 
mane, and they felt rough under the finger, while others, increased 
to 150 times their size, were not more than the 30th part of an 
inch in diameter : the latter were incomparably more numerous 
than the former. 
I have already said that the hairs of the intestinal mucus had, 
like those on the skin, a bulbous enlargement at the base. I 
have sometimes seen this with the unassisted eye, but at other 
times I have been obliged to M. Lassaigne, who has beautifully 
developed them by means of the microscope. 
The bulb being isolated has a somewhat ovoid form, and inti- 
mately adheres by means of its base to the chorion of the mucous 
coat. When it is separated by force, there remain some small 
broken filaments of slight consistence. These bulbs are some- 
times agglomerated together, and the hairs which protrude from 
them, unequal in length and in thickness, diverge at the approach 
to the free surface of the mucous coat. These agglomerations 
