Williams, Fisher, and Udall: The Spavin Group. 31 
was used for stud purposes on a near-by farm on an excellent 
band of roadster mares, where for years he bred choice stock, 
none of which, we are assured, showed any tendency to spavin 
or other affection of the group. Dr. Fisher contributes an 
observation on a California breeding ranch where a number 
of foals were confined in paddocks and highly fed. Osteo-poro- 
sis became general, some perished, the remainder were then 
removed to a hillside pasture one-half mile distant, where they 
promptly recovered. 
The only clinical evidence of heredity which we have been 
able to observe is the occurrences of the disease among offspring 
under the same conditions as those which produced it in the 
affected parent, while affected animals removed from the sur- 
roundings in which they acquired the malady do not transmit 
it to their offspring. We hold that a hereditary disease is 
cosmopolitan, knows no geographical limitations, and is not 
overcome by such environments as climate, food, or housing, 
and, taking this view, we cannot admit heredity as a cause of 
spavin or its allies. . 2 
We believe, however, that hereditary peculiarities in con- 
formation may tend to predetermine, in case the disease does 
arise, whether it shall appear in the form of spavin, ringbone, 
or other affection. 
RHEUMATISM. It is exceedingly difficult to arrive at any 
definite conclusion as to the réle played in the causation of 
this group of affections’ by the oft alleged rheumatism. The 
fundamental difficulty in arriving at a conclusion is the inse- 
curity of our definition of the term, we having as yet determined 
no rheumatism lesion which can serve to clearly distinguish that 
affection, whether in man or animals, while in the disease under 
consideration we have lesions of quite a definite character, not 
capable of differentiation among possibly two or three different 
maladies, it is true, but by no means suggestive of rheumatism 
as described in man. 
If we attempt to draw our conclusions from the disease 
known as rheumatism in man, the symptomatology is very un- 
like. We have occasional shifting of lameness in a few cases, 
it is true, but, as a rule, it is in a way permanent in the affected 
part, and, while rheumatism in man is ordinarily sudden in its 
onset, spavin and its allies generally come on insidiously, and 
only rarely appear suddenly. It seems to us that we are not 
