52 Thirl //-Firs! Ainiinil Mcclliif/ 



attempts of this sort, tlu'se |)rovi'(l to l)c' failun's. Only twice did 

 I succeed in artificial fertilization. On one of these occasions 

 the female was seined from the nest after she had hegun to 

 spawn. She could then l)e readily stripped. The male was cut 

 open and the eggs were fertili/A'd with the crushed testes. A1)()ut 

 75 per cent of the eggs hatched on a Avire tray, in running water, 

 the eggs heing fanned clean every day with a feather. 



In the second case the fish were seined while spawning and 

 it w^as found that in the case of one female, pressui'e on the ahdo 

 men caiised a reddish papilla to protrude from the vent. This 

 had the appearance of a mend)rane closing the vent. It was 

 pinched off and the female then stripped readily and the eggs 

 were fertilized and hatched. 



3. Pond ( 'uUurc. 



Having al)andoned artificial fertilization, our attention was 

 next turned to pond culiurc and this we have carried on for 

 al)out six years. Our earlier ponds were not of a sort to furnish 

 natural spawning ground. For this reason we constructed along 

 side each of the large ponds, six smaUer ])onds to l)e used as 

 spawning ponds. Each of these was about IG by '34 feet. 16 

 inches deep, with gravel Ijottom, and was connected to the ceai- 

 tral pond by a 4 foot channel. 



The fish entered these and s])a\vne(l. In one case we had 

 eight nests in a single pond of tliis sort. Where as numy nests 

 as this were made, usually hut one or two of them came to any 

 good, the others l)eing destroyed by the fighting of the male fish. 

 Ordinarily, but one or two nests were bnilt in each spawning 

 pond. The male fish first to entt'r and begin th.e construction of 

 a nest, generally n'garded the wliole pond as hix ju'operty and 

 liebl it against those that tried to entei' after him. On one occa- 

 sion the male thus holding the pond was attacked l)y ten or 

 twelve other males at one time and after a long struggle was 

 kilh'd and his nest destroyed. 



4. I now gave w\) the altem]it to use small s]»awning ponds 

 and had nt'ai'ly all my ponds made of good size and with a cen- 

 tral k'ettle and sballow shore area — as already described. The 

 ])robleni now was to ]ii'evenl the fighting of tlie male lish and the 

 consequent destruction of nests and eggs. 1 finally hit upon 



