h 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 18 to 36 inches deep
to the outlet. Where the topography of the ground will permit it is
better to have the nurseries immediately 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 water of spawning pond. If the location is infested
with crawfish or snakes the nurseries should be protected by wire
screens. The spawning nursery ponds may be combined by constructing one
comparatively long pond, narrow near the middle, so that the general
shape would be like an hour-glass. Across the narrow part is to be
stretched a screen of one-quarter inch wire cloth, which will confine
the spawners to the deeper end of the pond, while the fry or hatching
spawn will be kept separate. This form of pond is advantageous where
for any reason only a few ponds can be built. Between all ponds that
are connected they should be screened where water runs from one pond to
the other, that is, at the inlet and outlets.

Each pond should be surrounded by one-half inch wire mesh two feet
high. This makes a protection to the ponds from enemies, and also keeps
the Frogs confined to the ponds they are intended.

Care of Ponds.

The accumulated decayed matter ought to be occasionally removed. The
frequency of this depends on character of the water supply, the amount
of silt it brings into the ponds, the character of the soil, and on the
thoroughness of the yearly removal of the surplus vegetation. Care
should be taken that the ponds do not become offensive with stagnant
water and rotten vegetation. This condition is detrimental to large
production; while abundant pond vegetation is favorable to a large
production of fry it must not become decayed. It is sometimes so
luxuriant that it settles down in a blanket-like mass and smothers and
pens in many of the young Frogs. Under such conditions it should be
removed frequently. This can be done by lowering the ponds, if they are
built so they can be drawn off, which is a very desirable and
convenient way if the topography of the land will permit. A strong
flat-bottom boat should be made, in which can be taken the surplus
matted vegetation and carried off. At each end of the boat a ring
should be fastened, through which stakes can be driven t