10 Williams, Fisher, and Udall: The Spavin Group. 
end of the bone, bring about serious deformities in the joint. 
The external ridge loses its cleanness of outline, flattens down 
and becomes practically level with the bottom of the sulcus, 
while the internal trochlear ridge puffs up, enlarges in every 
direction, is rounded and obtuse everywhere; the trochlea has 
lost its function as a conduit for the patella and the efficiency 
of the joint is permanently and incurably destroyed. Compare 
Figs. VIII and IX. If we examine one of these articular cav- 
ities, it is found filled with an excessive amount of transparent 
or semi-transparent, faintly reddish or yellowish, thin synovia. 
The synovial papille are hypertrophied, greatly thickened and 
elongated, as shown at SM in Fig. VIII, and’ some of the more 
prominent are calcified at their free extremities, as shown at 
N, while another nodule, N+, is attached to it by a narrow neck, 
which time or accident may cause to part, and a free body in 
the joint result. 
In many cases the articular capsule is thickened and indu- 
rated, sometimes becoming enormously so to the extent of one- 
half to one inch of dense fibrous tissue, and, rarely, within 
this dense mass may be found large masses of necrotic tissue 
debris, as shown in Fig. IT at D D. 
The following portions, to and including page 208, is an ab- 
stract of the thesis already referred to. The outline of the work 
was planned by Professor W. L. Williams, and the microscopical 
technique largely under the supervision of Professor: V. A. 
Moore. 
MatertaL AND Meruops or Invesrication: — In the investi- 
gation of this disease we have had recourse to the clinical cases 
of the New York State Veterinary College. The material for 
both clinical and post mortem examination has been more than 
sufficient to occupy the available time devoted to the work. In 
some cases the history of the patient has been somewhat deficient, 
yet enough has been given with the majority of them to trace 
the origin and character of the clinical symptoms. 
The following scheme has been employed as a working basis, 
but the amount of time required for carrying out the experiments 
has of necessity confined us to a limited portion of the original 
outline. 
