728 



CIRCULATORY APPARATUS. 



point. The operation is usually performed on the angular vein of 

 the eye, the external saphenous vein, or the subcutaneous vein of 

 the forearm. 



In operating on the facial vein the animal's head is firmly held, 

 the operator compresses with the fingers of his left hand the facial 

 vein at the point where it passes into the maxillary fissure, and with 

 a lancet opens the angular vein of the eye or one of the other 

 branches of origin which project prominently beneath the skin. 

 Bleeding ceases as soon as the pressure is relaxed. 



In the case of the external saphenous vein, the vein is raised by 

 compressing the middle region of the limb and the vessel is opened 

 with a lancet, a little above and towards the outside of the hock. 



The sul^cutaneous vein of 

 the forearm can be raised 

 by compressing the fore liml) 

 below the elbow. The vein 

 is visible throughout the 

 length of the inner surface 

 of the radius, and can easily 

 be opened with a lancet. 



It is also possible to with- 

 draw small quantities of blood 

 by opening the marginal veins 

 of the ear. 



^.sc.'rA>}^;r 



Fig. 294. — Angular vein of the eye and 

 facial vein. 



BLEEDING IN THE PIG. 



Breeders sometimes bleed 

 by slitting one of the animal's 

 ears or cutting the tail. It 

 is preferable to bleed with a lancet from the marginal veins of the 

 ear, the external saphenous vein a little above the hock, or the sub- 

 cutaneous vein of the forearm. 



SETONS, ROWELS, PLUGS, OR ISSUES. 



Although the application of setons is still practised in horses, that 

 of "issues" has largely been given up in bovine animals, although 

 some practitioners still regard issues as of considerable value and 

 as producing efi'ects similar to, or better than, those of sinapisms. 



They are usually inserted in the region of the dewlap ; the materials 

 employed comprise black and white hellebore, veratrine and stems of 

 clematis. 



