458 
ON THE PRODUCTION OF HAIR ON THE 
and also in the colon, and particularly towards the pelvic and 
gastric curvatures. 
I have found them in many horses, but less frequently than at 
the places which I have mentioned, in the whole extent of the 
folds of the colon — in the caecum, principally towards it base, 
and especially at its insertion into the small intestine, and in 
the small intestine just beyond the insertion of the biliary and 
pancreatic ducts. I have never found them in the ileum, nor 
in the rectum ; and I have only once found them in the floating 
portion of the colon. I have almost uniformly found some hairs 
in the right extremity of the stomach, near the pylorus, but never 
in the cardiac portion. 
When horses have died in consequence of intestinal haemor- 
rhage, or any other disease that has produced considerable red- 
ness of the mucous coat of the intestine, the hairs are more easily 
to be seen, on account of their colour, which is generally lighter 
than that of the mucous coat ; and also because, with the blood, 
much of the natural mucus has been carried away, and the 
hairs have been left exposed ; and, lastly, because the accumu- 
lation of bloody serosity in the sub-mucous cellular tissue has 
caused the bulb of the hair to project, and has rendered its free 
extremity more evident to the sight and the touch. 
In other circumstances it is somewhat difficult to perceive the 
hairs with the unassisted eye, so that it is necessary to recollect 
the regions in which they are most commonly found, and to 
wash the membrane, and to remove the mucus with which it is 
lined, in order to leave the hairs as bare as possible. By means 
of a microscope or a lens they are very easily discovered. 
The hairs are not of precisely the same character in every 
horse. In the horse of heavy draught, the Belgian, Boulonnaise, 
Picardy, having a thick skin, well covered with coarse and long 
and numerous hairs, the hairs on the intestines are also long and 
coarse, and easily perceived. 
The age of the animal seems to make very little difference, 
only I think I have remarked, that adult and old subjects have 
more hairs on the intestines than those that are young. On very 
young horses they are scarcely or not at all to be perceived ; but 
I cannot tell the age at which they begin to make their ap- 
pearance # . 
I am inclined to believe that, once developed in the intestine, 
* The hairs that are found in the meconium, at the opening of the foetus, 
are not they derived, in part at least, from the mucous coat of the intestines ? 
M. Rigot found, at the same time, some detached hairs in the intestine of a 
foetus, and some others slightly adherent to the mucous coat of the intestine. 
