TROPICAL AQUARIUM FISHES 183 
Fic. 131. Japanese SpatTerpock (Reduced two-thirds) 
The Japanese Spatterdock, Alisma spec., has leaves of a considerably 
darker sage green, broader at the base. It is a continuous grower, has no 
aerial leaves and multiplies readily at the rhizome. Altogether a satisfac- 
tory plant for the large aquarium. 
FONTINALIS 
Known as Willowmoss these plants are found attached to stones 
or other substantial objects. They are of a pleasing dark-green color and 
have the advantage of doing well in a subdued light, although a moderate 
amount of direct sun does them no harm. 
Fontinalis antipyretica grows in long branching form, with leaves 
closely adhering to the stem. It occurs in cold-water streams and rivers, 
being very plentiful in some localities but is not freely distributed. 
Fontinalis gracilis is very much smaller and threadlike, the leaves 
being so small as to appear like a roughness on the stem. In the aquarium 
this plant seems to have a faculty of soon becoming covered with sedi- 
ment. Indeed some aquarists find it useful to clear the water. As soon 
as the plant becomes well covered it is taken out, rinsed off and returned. 
As the stems are strong they stand this treatment successfully. A stone 
containing a thick bunch of Fontinalis gracilis is an attractive feature in 
the aquarium. It is a slow grower. The new leaves are bright green but 
soon turn to a dark sage color. 
