Castration of Animals with the Burdizzo Pincers. 



419 



operation unaided tlie modified instrument of Fig. 2b offers undoubted 

 advantages. 



Farmers have sometimes asked \un\ tlie cords caD ()e crushed 

 under the bag without cutting the skin, and it may therefore be 

 explained that the technique of the operation is based upon the differ* 

 ence in resistance to pressure between the tissues of the scrotum and 

 of the testicular cord. The skin of the scrotum, and the fibrous mem- 

 brane (7'irnica vafjinnlis) containing the cords, resist the pressure of 

 the pincers (Fig. 3a, Fig. 4 «, Fig. 6</, h, c), while the blood-vessels 

 and the spermatic ducts of the cords are crushed and obliterated 

 (Fig. 3b and Fig. 6 a, h, c). The blood circulation is thu^s destroyed, 

 with the result that the testicles die as soon as the operation is com- 

 pleted. Haemorrhage is limited to a small clot of blood, since bleed- 

 ing into the bag {Tuuica ^vaginalis comvLunis) is prevented by the 

 fibrous membranes of the cord (Tunica vaginalis propria). 



Fig. 5.— « Testicle ot a 20 days old lamb, three days after castration. (The testicle 

 is congested, the cord is swollen.) h Testicle of a 3 months' old lamb, two months 

 after castration. (The testicle is shown cut open. The vital part of the o-land 

 was reduced to a thick turbid liquid.) c Atrophied testicle of a lamb 6 months 

 old. which was castrated three months before death. (The testicle replaced by a 

 lump of fibrous tissue and fat, the size of a coffee aiain.) 



Farmers have also inquired why it is that the testicles are with- 

 drawn in the scrotum iminediately after crushing the cords. The 

 reason is that the red muscular band which runs along the testicular 

 cord is not cut by the pincers, and on contraction causes a sudden 

 ascent of the testicles. The obstructed circulation of the blood in the 

 testicular tissue (passive hyperaemia) is soon followed by an intense 

 " haemorrhagic infiltration" on the day of the operation (Fig. ba). 



