450 ORGANIC LESION OF TIIE PYLORUS IN THE HORSE. 
intestine, it is that we find organic alterations of extra¬ 
ordinary character. The exterior surface of the ovoid 
bulging portion of the duodenum presents groups of black 
elevations of the magnitude of peas, of which some are round, 
others irregularly linear. They cover a space two decimetres 
in height by about one in breadth, having marked intervals. 
Throughout this papillated part, the fleshy coat of the gut 
is at least triple its natural thickness, and presents a close 
texture and greyish colour. We are much inclined to think 
that this change has something melanotic in its nature—a 
supposition favoured in some degree by the colour of the 
animal (grey). We regret not having subjected the matter 
to analysis, which might have settled the question. We 
feel bound to add that no traces of melanosis were to be dis¬ 
covered in those parts in which the disease is ordinarily 
found. 
The internal surface, extending from the aperture of the 
stomach along the duodenum to about two decimetres in 
length, is entirely coated with a thick layer of greyish 
curdly pus, having an infectious odour. The mucous fol¬ 
licles were considerably hypertrophied. And all this was 
more remarkable around the circular bulge here made by 
the pylorus. 
The thoracic portion of the oesophagus exhibited also remark¬ 
able alteration. Instead of its muscular coat being triply 
thick and close in texture along its course posterior to the 
heart, it has became extenuated and flaccid, and the more 
so the nearer it approaches the stomach, in which, as was 
before observed, it terminates in the form of a reversed 
funnel. 
If now 7 w r e make an attempt, through analysis of these 
various marked changes, to account for this pathological 
phenomenon, it will be easy for us to show that the pyogenic 
transformation of the pylorus is the principal agent. And 
we regard it as operative in this manner:—This lesion, after 
more or less duration, arrives at that intensity that it either 
sets up opposition or difficulty to the egress of alimentary 
matters from the stomach to the duodenum. Such an ob¬ 
stacle cannot here be followed by over-repletion of stomach. 
Such repletion for any length of time being unendurable, 
muscular contraction is set up in the stomach, but which 
becomes, under the growing distension, weaker and weaker, 
as much from distension of muscular fibre as from exhaustion 
of nervous energy. This nervous exhaustion is succeeded by 
temporary paralysis, which, affecting tht^ substance of the 
pyloric orifice, produces, according to M. Mignon, closure 
