THE NEW ART OF BREEDING FISH. 47 



thumbs upon the thorax and his fingers upon the 

 animal's sides, presses from top to bottom the enor- 

 mous mass of eggs which distend the coats of the 

 belly. The vertical position in which the fish is 

 held usually suffices to press out the eggs nearest the 

 opening, and the pressure of the hands, repeated 

 several times, wiU successively bring all the rest. 



The easy expulsion of the eggs proves their ma- 

 turity, for it shows they are detached from the ova- 

 ries ; but it does not prove absolutely their capabi- 

 lity of being fecundated. For there are some cases, 

 the causes of which we have not ascertained, where 

 the female being in a stream and at liberty^ and 

 having gone her full time, and her eggs being ready 

 for delivery, yet she does not or cannot free herself 

 from them, and being thus retained past their time 

 they lose their reproductive faculty. 



Experienced persons easily recognize eggs of this 

 sort by two evident characteristics : one is the flow- 

 ing out with them of a foreign matter, of which there 

 is no trace in their normal state, which gives a mud- 

 dy hue to the water when the eggs begin to fall into 

 it ; another is, the white color of these eggs when 

 they come in contact with the water. When neither 

 of these appearances is observed, we may be almost 

 sure the operation will be successful ; for the eggs wiR 

 then be in good condition. But in all cases we must 

 guard against allowing too great a quantity of eggs 

 to fall into one vessel, for if those on the bottom are 

 covered over by too many others, they will not per- 



