LXII 
either side of an island which contains the ponds devoted to 
breeding purposes. 
There is nothing special to attract our attention in the con- 
struction of these three ponds, except the depressions near 
the outlet (known as collectors or kettles), into which the iish 
are gradually drawn when the water is taken from the ponds. 
The ponds marked a, b, c, d , e and /*, are used exclusively 
for breeding purposes. The outlet of each of these ponds 
connects with a drain-pipe which discharges itself into the 
Potomac River. At the outlet of each there is a kettle, as 
in those just mentioned, in which the fish are collected. 
These ponds are not level, sloping from two inches to 
to four feet (in depth), the deepest parts being at the collectors. 
They are well furnished with aquatic plants, and a portion of 
those marked a and b are provided with movable partitions 
constructed in the shallow parts. These separate the more 
open space of the pond from that of a denser aquatic growth. 
The spawning fish eagerly seek those portions well provided 
with grasses, and after depositing their eggs they are allowed to 
return to the more open space. The partitions are then put in 
place to prevent their re-visiting the grassy parts and disturb- 
ing their eggs. 
Figures 1, 2, 3, 4, 5 and 6 represent tanks into which the 
water can be introduced. These are used for stowing and 
sorting the fish. No. 7 represents the watch-house occupied 
by the guard and attendants. 
The thorough confidence of Prof. Baird in the ultimate 
success of the experiment of introducing this fish into Amer- 
ican waters is shown by his persistent and repeated efforts to 
import them. The good results have more than realized our 
expectations, for the growth and weight of the imported fish 
and the excellence of their offspring have been greater than 
under the most favorable circumstances in Europe. 
The normal weight attained by the carp, in Europe, when 
three years old (the age of maturity), is said to be from three 
to four pounds. Those, however, that were imported into 
this country now weigh from nine to ten pounds. 
