BULLETIN OF THE UNITED STATES FISH COMMISSION. 285 



measuring when mature about one-seventh of an inch in diameter. After 

 impregnation the egg does not increase mucli in size in consequence of 

 the absorption of water from without, as in the case of the eggs of the 

 shad and whitefish. The vitellus, in consequence of this, lies ahnost in 

 contact with the egg-membrane, as shown in Fig. 1. The egg -membrane 

 is without pore canals, and is therefore not a zona radiata like that of the 

 shad and salmon. ]t is about -^^ of an inch in thickness, which is 

 more than six times that of the zona radiata of the shad egg. The 

 fibers or filaments which arise from the surface of the egg are cylindri- 

 cal and taper towards their free extremities. The attached end of the 

 fiber is swollen into a truncated cone, which is joined to the surface of 

 the egg-membrane by its base. From the truncated apex of the cone 

 the fiber arises, and a very distinct transverse line indicates the point 

 where the former joins the latter. The fibers may be forcibly pulled off 

 of the membrane; when this is done a slight concave depression remains 

 on the surface of tlie latter, marking the point of attachment of the con- 

 ical base of the filament or thread. The thickness of the threads is 

 about the same as that of the egg-membrane, and they are apparently 

 composed of the same material, as indicated by their color and behavior 

 towards reagents. An examination of the ovaries of different females 

 in various stages of maturity reveals the fact that the fibers are tightly 

 coiled about the egg-membrane in the immature condition in the ova- 

 rian follicles, and that they are also wound round the globular egg in 

 but one plane, which we may designate as the equatorial plane. This 

 appears to be the tendency of the fibers on the eggs of other Scomber- 

 esocoids as well as in Chirostoma. After extrusion the fibers on the egg 

 uncoil and stand out, looped and twisted together in all directions, a« 

 shown in Fig. 1. The length of the fibers varies, but it does not usually 

 much exceed the diameter of the egg. 



The ovary of the silver gar is a very long, simple cylindrical pouch, 

 A^arying in size and length very greatly, according to the degree of ma- 

 turity of its contents, which are discharged by way of a wide oviduct 

 opening behind the vent. The ovary when quite mature is sometimes 

 a foot in length and nearly an inch in diameter. As usual in fishes the 

 male is notably smaller than the female, and the milt or spermary is a 

 simple, elongate, somewhat peculiarly lobulated, three-sided organ, ex- 

 tending, like the ovary in the female, for the greater part of the length 

 of the body cavity; it empties its products into the water through a 

 wide sperm duct behind the vent. The genesis of the spermatozoa is 

 effected in much the same way as in the Spanish mackerel, as is shown 

 by sections of the organ in my possession. 



As in many other teleostean fishes the germinal protoplasm of the ma- 

 ture egg covers the vitellus as a thin envelope; in the egg of Belone it is 

 extremely thin, but there is a great number of very transparent, refrin- 

 gent, minute vesicles scattered through this germinal pellicle, which is 

 of uniform thickness over the whole vitellus. It has occurred to me that 



