450 
W. L. WILLIAMS. 
invasion probable, while the blood and licpiids within the tissues 
of the cord were retained, serving as an excellent ciiltnre 
inedinm for putrefactive inicro-oinanisms. 
The patellar dislocations were evidently dne to the hy])cr- 
secretion of .synovia, which, distending the sacs, lifted the patelhe 
ont of their grooves and beyond their retaining ridges when a 
combination of forces determined an outward luxation. 
no. 
IV.—ANT1':RH)K 
Vll<;w OK LKKT STlKLl-: WITH 
CAKSULK Ol’KNKI). 
!<' K M O K O- K AT lO. L A R 
(1 I'einoral troclilea. <' Location of patella. 
/> b Synovial clots. d Abraded external trochlear ridge. 
It has been held that external luxation of the patella is dne 
to the lesser elevation of the external trochlear ridge, bnt this 
alone in such a case conld not determine the direction of the 
dislocation nor even cause luxation at all. In this “floating” 
luxation the intra-articnlar pre.ssnre is alike in every direction, 
the walls of the capsule yielding at the various parts in inver.se 
ratio to their strength, supplemented by other contignons liga- 
