DISEASES OF THE GENERATIVE ORGANS. 183 



calf passes most easily with its back upward, and when turned with 

 its back to one side calving is always tardy and may be difficult or 

 impossible. The obvious remedy is to rotate the calf on its own axis 

 until its spine turns toward the spine of the cow. The operation is 

 not difficult if the body of the calf is not yet fixed in the passages. 

 The presenting feet are twisted over each other in the direction 

 desired, and this is continued until the head and spine have assumed 

 their proper place. If the body is firmly engaged in the passages the 

 skin of the whole engaged, portion should be freely lubricated with 

 lard, and the limbs and head twisted over each other as above. The 

 limbs may be twisted by an assistant where the head is manipulated 

 by the operator, who drags on the rope turned halfway round the 

 limbs and assists in the rotation with his other hand in the passages. 



HEAD AND FORE FEET PRESENTED — BACK TURNED DOWN TOWARD 



THE UDDER. 



This position (PI. XVI, fig. 6) is unnatural, and the parturition is 

 difficult for two reasons: First, the natural curvature of the fetus is 

 opposed to the natural curvature of the passages; and, second, the 

 thickest part of the body of the calf (the upper) is engaged in the 

 narrowest part of the passage of the pelvis (the lower). Yet unless 

 the calf is especially large and the pelvis of the cow narrow, parturi- 

 tion may usually be accomplished in this way spontaneously or with 

 very little assistance in the way of traction on the limbs. If this can 

 not be accomplished, two courses are open : First, to rotate the calf as 

 when the back is turned to one side ; and, second, to push back the 

 presenting fore limbs and head and search for and bring up the hind 

 limbs, when the presentation will be a natural posterior one. 



PRESENTATION OE THE HIND FEET WITH THE BACK TURNED TO ONE 



SIDE OR DOWNWARD. 



These are the exact counterparts of the two conditions last described, 

 are beset with similar drawbacks, and are to be dealt with on the 

 same general principles. (PI. XVII, fig. 4.) With the back turned 

 to one side the body should be rotated until the back turns toward 

 the spine of the dam, and with the back turned down it must be 

 extracted in that position (care being taken that the feet do not per- 

 forate the roof of the vagina) or it must be rotated on its own axis until 

 the back turns upward, or the hind limbs must be pushed back and 

 the fore limbs and head advanced, when the presentation will be a 

 natural anterior one. 



IMPACTION OF TWINS IN THE PASSAGE. 



It is very rare to have twins enter the passages together so as to 

 become firmly impacted. As a rule each of the twins has its own sep- 

 arate membranes, and as the water bags of the one will naturally first 

 enter and be the first to burst, so the calf which occupied those mem- 



