Williams, Fisher, and Udall: The Spavin Group. 11 
I. Gross examination. 
A. Physical. 
(a) History of animal. 
(b) Character of lameness (local, general). 
(c) General condition of the patient. 
B, Anatomical examination of joints and extremities, 
(a) Amount and character of synovial fluid. 
(b) Character of synovial membranes and capsular ligaments. 
(c) Condition of articular cartilage. 
(d) Character of deformity. 
II. Urine analysis. 
(a) Determination of reaction. 
(b) Amount of phosophates and other solids. 
III. Pathological examination of the tissues. 
A. Bone (macroscopic and microscopic changes). 
Preparations of bone for microscopic examination were made 
in the following manner: Small pieces of fresh tissue were fixed 
in an alcoholic-sublimate solution, or in picric alcohol; these 
were hardened in ethyl alcohol by placing them first in that of 
fifty per cent. strength, then removed to that of sixty-seven per 
cent., eighty-two per cent., and ninety-five per cent. respectively ; 
the hardening process being complete in from three to five days. 
Specimens that were fixed in the alcoholic solution of corrosive 
sublimate and hardened in alcohol were employed for filed prepa- 
rations, which were excellent for demonstrating the inorganic 
structure of the bone. To bring out the structure of both the 
organic and inorganic tissue it is necessary to decalcify. The 
following fluid was used for this purpose: sixty-seven per cent. 
alcohol, ninety-seven parts; concentrated nitric acid, three parts. 
The methods of technique may be found in “Normal Histol- 
ogy,” Piersol. The sections were stained in hematoxylin and 
picro-fuchsin and mounted in Canada balsam. Several other 
stains were used, but the above were the only ones that gave 
satisfaction. 
EXAMINATION OF SUBJECTS. 
Case 1.—A bay mare fifteen years of age, brought to the clinic in 
the spring of 1900 to be treated for lameness in the right hind limb. 
Symptoms; anemia; slight ventral hernia; lameness very marked, 
especially in the hind limbs; well developed gonitis on the right side; 
upon urging the animal to trot she appeared to be lame in every joint. 
Autopsy:— Left anterior extremity: scapulo-humeral articulation; the 
articular cartilage was roughened on the head of the humerus; the syno- 
vial membrane discolored.. Elbow joint: the cartilage on the trochlea of 
