10 FISH CULTURE 



surface. Such construction may be considered 

 as ideal, because perfect drainage is then cer- 

 tain. 



Earlier bass-culture was conducted in ponds 

 of very small dimensions, but with advancing 

 experience the area for breeding-fisb was in- 

 creased, until now some almost appiroach the 

 size of lakes. Few now in use for breeders are 

 less than 200 by 75 feet; and the tendency is 

 to make them much larger. Four to five acres, 

 however, is about the limit that can conveniently 

 be cared for; and those who breed bass feel that 

 even that space can be more satisfactorily 

 handled, and with better results, when divided 

 into two or three breeding-ponds than as a 

 single body of water. Owing to the expense of 

 constructing very large ponds, and the length 

 of time required for their completion, it is ad- 

 visable when starting a bass plant to build one 

 or two ponds about 300 by 100 feet in order that 

 there may be an early stock of young fish. 



Depth and Bottom. — The bottom of a pond 

 for fish-cultural purposes is divided into two 

 parts, one called the "kettle," and the other the 

 "spawning-shelf," or simply "shelf." The 



