I'ungoused, ami are protected from unfavorable weatlier conditions. Sliould liail tlireaten. a strong 

 wind blow, or the air temperature fall suddenly, the ponds must be quickly covered with matting or 

 screens. 



As a general thing, the hatching ponds receive and require no fresh water while incubation 

 is in progress. It is sometimes desiraljle, however, to effect a change of water, particularly if the 

 temperature becomes very high. 



The hatching period is comparatively short, and normally occupies eight to nine days at a water 

 temperature of 60 to 65 °F. A rising temperature may reduce the hatching time as much as one- 

 half, but a very rapid development of the eggs is unfavorable. On the other hand a fall in the water 

 temperature may prolong the hatching one-third to one-half, but a gieatly retarded incubation is 

 likewise unfavorable, especially in that the young are not of uniform size. A peculiaritv of the gold- 

 fish egg is that the embryo covers nearly the entire circumference of the vitellus, and the yolksac is 

 comparatively small and very granular. 



