56 Fresh Water Aquarium 



oval, slightly heart-shaped on the base, of 

 a brownish color and a leathery appearance. 

 The submerged leaves disappear as soon as 

 the floating leaves form. 



Potamogcton amplifolius. This pondweed, 

 of which we give a photographic repro- 

 duction, is one of the best aquarium plants, 

 a splendid grower, a good oxygenator and 

 highly ornamental on account of its graceful 

 form and its exceptionally vivid green color. 

 One who has collected the plant in its native 

 waters will hardly recognize it in our pic- 

 ture. Only the few bottom leaves, grown 

 before it was collected, indicate its normal 

 form. The after growth made in the aqua- 

 rium differs so radically from the wild plant 

 that it would never be taken for what it 

 actually is. While all Potamogetons are 

 subject to variations caused by the habitat 

 and local conditions, we never observed so 

 considerable a change as in this case. It 

 would be interesting to see, if the plant, when 

 transplanted from the aquarium to outside 



