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-fish was in- 

 creased, until now some almost approach 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 



