AQUATIC PLANTS IN POND CULTURE. 11 
of some of this luxuriant growth would have resulted in a decrease 
in the production of young fish is theoretical. This station had been 
in operation nearly thirty years, and the lakes contained an unusually 
large number of plants, upon which Mr. C. K. Green, the last super- 
intendent of the station, makes the following observations: 
The hornwort (Ceratophyllum demersum) is especially good as a 
food producer and for shelter, and is fairly good for shade; is a good 
oxygenator and a good aquarium plant, has little root anchorage, and 
will grow over hard bottom. It is found in 2 to 4 feet of water, ex- 
Fic. 4.—Fanwort (Cabomba 
caroliniana). Found in 
ponds and_ slow _— streams, 
Fic. 38.—Hornwort (Ceratophyllum demer- southern Illinois to North 
sum). Found in ponds and slow streams Carolina, south to Florida 
throughout North America, except extreme and Texas. (After Britton & 
north. (After Britton & Brown.) Brown.) 
tending to the surface, but not above it. The superintendent consid- 
ered it the best plant in his ponds. 
Fanwort (Cabomba caroliniana) also is especially good as a food 
producer, for shelter, and for aquarium work, and is given second 
place. It is regarded as a good oxygenator and fairly good for shade 
and, like the hornwort, has little root anchorage and will grow on 
hard bottom. It is found in 1 to 4 feet of water, and extends nearly 
to the surface. 
The curled-leaved pondweed (Potamogeton crispus), a good food 
producer and oxygenator, good for shelter and for shade and orna- 
ment, is one of the earliest plants to put forth shoots, and is there- 
fore valuable for early-spawning fishes like the goldfish and carp. It 
