SEXUAL CHARACTERS OF SOME DOMESTIC BIRDS. 11 



In determining the degree of anesthesia, reUance is placed upon the 

 amount of relaxation of the neck, the condition of the eyes — i. e., 

 whether open or closed — and the rate and depth of respiration. With 

 good working anesthesia the neck is hmp, the eyes closed, and the 

 respiration deep and regular. Too much ether is shown by shallow, 

 rapid, but often slightly irregular respiration. Too little is indicated 

 by a rigid neck and often open eyes, though the bird gives few other 

 indications of sensibiUty. Rapid respiration is often observed with 

 too little ether. 



PRELIMINARY STEPS. 



The bird is fastened to the operating table by a cord around both 

 wings, which are drawn over the back, while the legs are similarly fas- 

 tened, but stretched at a medium tension in line with the long axis of 

 the body. The feathers are plucked from an area extending from the 

 fourth rib posteriorly over the thigh and from mid-hne of the back to 

 the center of the breast. An oblique incision is made through the skin 

 from near the mid-dorsal line, shghtly obliquely downward, following 

 the anterior margin of the sartorius ; then an incision is made between 

 the last two ribs. This incision should be as large as necessary for con- 

 venience and will vary in different cases, care being taken to avoid 

 extending the cut so far dorsally as to sever the spinal artery. The 

 ribs are drawn apart by hooks and chain or suitable spreader. 



REMOVAL OF TESTES. 



In the male, except in very young individuals, the area of attachment 

 of the testis is small, proportionally to the size of the organ. At the 

 age at which the testes are commonly removed in commercial caponiza- 

 tion the testes are ovoid in shape, while the vascular system is shghtly 

 developed. The connective tissue is also delicate, so that with modern 

 instruments the removal of the gonads is a simple matter. In the adult 

 the vascular supply has become well developed, the area of attach- 

 ment absolutely larger, while the connective tissues are tough, necessi- 

 tating the use of ligatures and knives in their removal. In the very 

 young bird the testes are dehcate; each has the form of a narrow cyUn- 

 der, pointed at both ends, which is attached along one side to the ihac, 

 rendering the removal correspondingly difficult. It may be readily 

 accomphshed, however, with a slender pair of curved forceps, but 

 much care must be taken to avoid rupturing the iliac or the testicle. 

 If the latter happens, it becomes very difficult to make a complete 

 removal. The best procedure yet found in removing these very young 

 testicles is to get one end started by picking carefully at the union with 

 the iUac; the testicle can then be peeled off by keeping hold of the 

 capsule on the iliac side with the forceps. Sometimes it may be found 

 desirable, after the end has been started, to push oE the testis with a wad 

 of cotton'. With older birds ordinary caponizing tools may be used. 



