PROBLEMS OF FISH AND FISHING 



303 



encouraged, to see who can have the most beautiful aquarium and the 

 most instructive one, and hold it longest without change of water. A de- 

 merit mark is deserved, and may be given, for every time a pupil permits 

 the water in his aquarium to become foul enough to require changing. 



In this way, by gaining experience through the year, the students 

 may keep the aquaria running in fine balance, each with some specimen 

 of native fish, and so afford a most instructive exhibition. This may be 

 held in connection with appropriate lec- 

 tures by specialists and a general discus- 

 sion of the plans which have been worked 

 out for the adequate stocking of local 

 waters. Whether we call it Fishes' Day 

 or make it a feature of more general exer- 

 cises will depend on community interests 

 and preferences. 



A few important features of such an 

 exhibition may be 



1. Species of value and relative impor- 

 tance of each. 



2. Habits and proper habitats of each 

 species (so far as these can be shown by 

 arrangement of aquaria). 



3. Table of spawning seasons ; pre- 

 served specimens of eggs and fry ; photo- 

 graphs and other pictures of fish nests; 

 diagrams of local waters, with distribution 

 of nesting places of different species. 



4. Eggs actually being hatched (Fig. 

 142) and fry being fed and reared for 

 distribution. 



FIG. 142. Tumbler hatchery 



Water running through funnel 



keeps eggs aerated. Author's 



design 



5. Foods of different species, with natural food supplies. 



6. Extermination of mosquitoes by fishes, with data from feeding 

 tests in the school aquaria and from park or pond waters properly stocked. 



7. Data of growth of different fishes, fed in different ways. 



8. Diagrams and records of production of home fish ponds. (Why 

 not have fish projects and fish clubs as well as corn clubs and pig 

 clubs?) 



9. Enemies of different fishes, and means of their control. 



10. Fish course, composed entirely of local varieties in season, 

 prepared by domestic-science classes for the exhibit luncheon. 



