50 



Aquatic JLitt 



the female and their replacement by other 

 two. 



In the fructification of the ova, as in 

 the case with most oviparous fishes where 

 they are gregarious and marriages com- 

 munistic, the female discharges the germs 

 of matter (ova) and the male the germs 

 of life (sperm), scattering them at ran- 

 dom among the most suitable weeds that 

 are on the surface of the water, the males 



micropyle, and that must take place be- 

 fore the ovum has found a lodgment on 

 the weeds or elsewhere ; therefore, there 

 is no necessity for the females to be 

 pressed by the males. 



Among the gregarious fish the males 

 have no clasping fins, as is the case with 

 some of the monogamous, or with some 

 that are monogamous for one season 

 only, especially those that are viviparous, 



TTae Autkor's Conservator)) 



always intermixing with the females. 

 When these germs or cells of matter are 

 once freed from the ovary, the male at 

 once discharges the sperms or cells of 

 life, which are microscopic. The cells 

 of the ova and the cells of the sperm are 

 rapidly churned up by the quick move- 

 ments of the excited fish. This prevents 

 them from at once adhering to the weeds 

 (the eggs are glutinous). Each ovum 

 receives one germ cell of life from the 

 sperms through the little gateway, the 



such as Gambusia affinis. 



The males of the carp referred to by 

 Darwin, as the breeding season ap- 

 proaches, develop excrescences on the 

 gill-covers and pectoral fins. The func- 

 tion of these excrescences is wholly inde- 

 pendent of the extrusion of the germ- 

 cells, but serves a purpose that leads up 

 to the maturity of the ova. That it is 

 essential for two or more males to accom- 

 uany a female to aid her to discharge her 

 ova is not exactly the law of reproduc- 



