48 POULTRY DISEASES 



ondary and provided with columnar epithelial cells. The ovi- 

 duct has great power of dilatation, but tears easily if the trac- 

 tion is too much in one direction. A rupture of the oviduct 

 sometimes occurs. 



THE MALE REPRODUCTIVE ORGANS 



The generative organs of the male fowl are the testes and 

 vas deferens or seminal tubules. 



In the cockerel, before sexual maturity, which is denoted 

 in physical appearance by the male bird crowing, the testicles, 

 two in number, are very small, measuring only about one-half 

 inch long and scarcely one-fourth inch in diameter. They 



Fig. 16. Generative Org.\ns of a Cockerel. 



a, the testicles; b, the rectum cut and turned back; c, the cloaca into which 

 the duct terminates; d, the vas deferens; e, the kidneys; f, the adrenal 

 gland; g, the lungs. 



resemble, in shape, a navy bean and are j^ellowish-white in 

 color. Fig, 16 illustrates the testes at a, and at d may be 

 seen the undeveloped vas deferens or seminal tubules. 



As the male bird becomes sexually active the testicles de- 

 velop to enormous size, measuring two inches in length and 

 seven-eighths of an inch in diameter, as illustrated in Pig. 17. 

 which is from a single comb AVhite Leghorn cock one year 

 old. 



The testis is made up of a globus major and glol)us minor, or 

 epididymis, the latter rather rudimentary. The gh)bus major 

 forms the major portion of the testicle. Tlie epididymis is 

 short and from it originates the vas deferens as shown in 

 Fig. 17, letter d. 



The testicular tissue is made up of fine intertwined sperm 



