ANATOMO-PATHOLOGIC STUDY OF RINGBONE AND SPAVIN. 995 
so large and deep-seated articular surfaces as those of the coro¬ 
nary joint. 
Spavin .—Opinions are at variance as to whether spavin, 
arthritis chronica deformans of man, commences peripherally 
as a periostitis , or centrally as. an osteo-arthritis of the hock 
bones. Does the lesion progress centripttally or centrifugally ? 
Most veterinarians are inclined to the former view and for this 
purpose I have examined about 40 specimens, which have been 
collected promiscuously at various times. I shall not here re¬ 
fer to the mechanism of the causation of hock diseases. 
Upon these specimens the following alterations were ob¬ 
served : 
7. No exostosis. Occult spavin—ankylosis of the scaphoid 
and large cuneiform. 
11. Ankylosis scaphoid, large and small cuneiform. 
10. Ankylosis scaphoid, large and small cuneiform and 
metatarsus. 
7. Ankylosis scaphoid, large and small cuneiform and 
cuboid. 
The remaining were of miscellaneous coossifications—be¬ 
tween the astragalus and calcis, astragalus and scaphoid (least 
frequent), the entire tarsus, etc. 
In all cases accompanied by an exostosis the inter-articular 
lesions were well advanced ; and in no case, excepting one, and 
this was excessively doubtful, was there any peripheral deposit 
with a normal state of the articular surfaces. 
The general order in which, from these observations, the 
hock bones became affected was as follows : The scaphoid and 
large cuneiforms, the three internal bones of the lower row, the 
lower row and the metatarsus, and finally the three internal 
bones of the lower row with the cuboid of the same row. If I 
am correct in making these deductions, the lesions of spavin 
should commence as a scaphoido-large cunean arthritis and, 
contrary to the frequent assertion, the small cuneiform was not 
the seat of the primary lesion. The so-called “occult ” spavin 
may therefore be a variety of spavin in its usual sense when the 
