PREFACE TO THE THIRD EDITION. v 



given case, another in a different patient where the same 

 operation is to be performed as for example, a milk cow is 

 best spayed through the vagina while a heifer must be 

 operated upon by an incision through the abdominal walls. 



Considerable stress has'been laid upon the surgical anato- 

 my of the parts involved in each operation ; some uses of 

 the various operations are mentioned ; some of the chief 

 dangers of each are pointed out and in some cases references 

 to literature upon the operation or the diseases for which 

 the operation is designed, are cited. 



Figures i, 2, 6, 7, 9, 10, 11, 15, 16 and 17 and Plates Nos. 

 XII, XIV, XVI, XXIII, XXIV, XXVII, XXVIII, 

 XXIX, XXXI, XXXIV, XXXV, are from Dr. Pfeiffer's 

 Operations-Cursus ; and the remaining Plates and figures 

 were either drawn under the direction of the author by 

 Mr. C. W. Furlong, formerly instructor in Industrial Draw- 

 ing and Art in Sibley College, Cornell University, or were 

 made from original photographs. 



W. Iv. Williams. 



Cornell University, March, igi2. 



