186 DISEASES OF CATTLE. 



The influence of disease in modifying growth in the earl}^ embryo, 

 increasing, decreasing, distorting, etc., is well illustrated in the 

 experiments of St. Hilaire and Valentine in varnishing, shaking, or 

 otherwise disturbing the connections of eggs and thereby producing 

 monstrosities. One can easily understand how inflammations and 

 other causes of disturbed circulation in the womb, fetal membranes, 

 or fetus would cause similar distortions and variations in the growing 

 offspring. It is doubtless largely in the same way that certain men- 

 tal disturbances of a ver}' susceptible dam affect the appearance of 

 the progeny. The monstrosities which seriously interfere with 

 calving are mainly such as consist in extra members or head, which 

 can not be admitted into the passages at the same time, where some 

 organ of the body has attained to extra size, where a blighted ovum 

 has been inclosed in the body of a more perfect one, or where the 

 body or limbs are so contracted or twisted that the calf must enter 

 the passagas doubled up. 



Treatment. — Extraction is sometimes possible by straightening the 

 distorted members by the force of traction ; in other cases the muscles 

 or tendons must be cut across on the side to which the body or limbs 

 are bent to allow of such straightening. Thus, the muscles on the con- 

 cave side of a wry neck or the cords behind the shank bones of a con- 

 tracted limb may be cut to allow of these parts being brought into the 

 passages, and there will still be wanting the methods demanded for 

 bringing up missing limbs or head, for which see paragraphs below. 

 In most cases of monstrosity by excess of overgrowth it becomes nec- 

 essary to cut off the supernumerary or overdeveloped parts, and in 

 this the same general principles must be followed as laid down in 

 "Embryotomy" (p. 204). 



TABLE OF WRONG PRESENTATIONS OF THE CALF. 



Simultaneous presentation of twins. 



Fore limbs. 



Head 



Limbs curved at the knee. Flexor tendons shortened. 



Limb crossed over the back of the neck. 



Limb bent back at the knee. 



Limb bent back from the shoulder. 



Head bent downward on the neck. 



Head and neck turned downward beneath the breast. 



Head turned to one side upon the side of the neck. 



Head and neck turned back on the side of the chest and 



abdomen. 

 Head turned upward and backward on the back. 



I Hind limbs rotated outward. Toes and stifles turned out- 

 ward. 

 Hind limbs bent forward, their feet resting in the pelvis. 



Transverse Back of the calf turned to the right or left side. 



Inverted -.. Back of the calf turned to the floor of the pelvis and udder. 



