At least one-fourth of each of the ponds should not be over 

 one foot in depth, and this portion should be planted with pond 

 weed (Potamogeton) and water weed (Elodea, or Anacharis) to 

 facilitate the production and growth of the minute animals which 

 furnish so large a part of the food for the Frogs at all stages of 

 growth. The rest of the pond should have a gradually sloping 

 bottom, and consequent increase depth to* the outlet (or drawoff), 

 where the water should be at least five feet deep, so that in drawing 

 off the ponds the stock can be assembled in a small area for sort- 

 ing, etc. The bottom of the ponds, preferable, soft muck, in which 

 the Frogs can bury themselves in cold weather and avoid against 

 danger of freezing. In the middle of all the ponds, except the 

 spawn hatching pond, water lilies should be planted, the large pods, 

 such as (Nymphea alba). These plants furnish hiding places from 

 fish hawks, also serve as a sun shade and stool for sunning during 

 summer. It is not advisable to place large bowlders in the pond, 

 as they are in the way of seining or netting, and furnish an acceptable 

 resort for crawfish, which are enemies when large. Nursery ponds 

 should be constructed to afford young, protection from enemies and 

 to produce the greatest quantity of insect life suited for their sus- 

 tenance, and this is better accomplished with a number of small 

 ponds than with one large one. A good working size for spawn 

 breeding is from 40 to 50 feet long, by 12 to 15 feet wide, with a 

 depth of from 1 8 to 36 inches deep to the outlet. Where the topog- 

 raphy of the ground will permit it is better to have the nurseries im- 

 mediately adjoining the spawning pond. With water supply from 

 same source, so that there will be but slight difference between the 

 temperature of the shallowest part of nursery pond and surface of 



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