722 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



In some other fishes, the ovaries resemble two ribbons (fig. 4), more or 

 less twisted, running along both sides of the intestine to the dorsal wall 

 of the abdominal cavity, as in the sturgeons, salmons, and also in the 

 eels. The ripe egg, when it separates from the ovary in the abdominal 

 cavity, passes through a hole which opens on the outside behind the 

 anus. 



The male organs of fish, or spermatic organs, commonly called milts 

 [testicles,] which produce the sperm — i. e., a fluid containing small organic 

 bodies, which, moving about, penetrate the egg, impregnate it, and start 

 the development of the embryo — are likewise of different forms. 



In the " pesci-cani " (dog-fish 7 i. e., Mustelus), the "rase " (ray, i. e., 

 Raja), &c, the male organs resemble two thin laminae (fig. 5) elongated, 

 twisted, and partly lobate, composed of partitions, from which small 

 tubes start, which unite and compose a somewhat larger tube, terminat- 

 ing in the right as well as the left side in a canal, which serves for the 

 emission of the sperm. 



Fig. 5. 



Fig. 6. 



Fig. 5. Testicles. 



a. Left testicle. 



b. Vasa efferentia. 



c. Left epididymis. 



d. Deferent canal. 



e. Intestine. 



/. Urinary bladder. 



cj. Left seminal vesicle. 



h. Opening of the deferent canals. 



i. Urethral orifice. 

 j. Cloaca. 



Fig. 6. Testicles. 



a. Abdominal wall. 



b. Dorsal wall. 



c. Left testicle. 



d. Left deferent canal. 



e. Intestine. 



/. Urinary bladder. 

 g. Anus. 

 ■' i. Genital orifice. 

 j. Urethral orifice. 



In the greater number of osseous Jish, the spermatic organs consist of 

 two elongated bodies (fig. G), more or less triangular, or in the form of 

 thin laminae, composed of compartments, which, beginning on the outer 

 surface, converge toward the interior of the organ, giving rise to a 

 canal called " vas deferens", which in many fishes consists of a net-work of 

 conduits; which " vasa", those of the opposite sides uniting, form a 

 single excretory canal, which debouches in many fish first in the urethra, 

 usually on a small papilla placed behind the anus. 



