necessary sunlight, which is vital to all of them. 

 It is only reasonable to suppose that the ele- 

 ments of plant nutrition are diffused throughout 

 water in which the decomposition of organic 

 substances is going on, and that living in such 

 a medium, absorption through the plant tissues 

 would be the simplest provision for their suste- 

 nance. 



Floating plants take their sustenance directly 

 from the water through roots provided for that 

 purpose though they are not anchored by them. 

 Yet these roots will quickly grow into the soil 

 if they can reach it. Why, therefore, should 

 not the stalks and leaves of submerged plants 

 take their nourishment directly from the water 

 and not necessarily from soil? 



Few people are able to grow cabomba though 

 it is the plant in most general use. Yet in a 

 properly conditioned aquarium it will root 

 quickly and grow luxuriantly. It is true that in 

 nature the most luxuriant growths of plants 

 occur where there is mud or much sediment 

 but may not that only mean that in such places, 

 which are more or less stagnant, the water 

 contains a greater proportion of nutritive ele- 

 ments? Plants in such places mature earlier and 

 become ragged and unsightly while those grow- 

 ing in sand bars where there is some current 

 are cleaner and brighter though apparently not 

 of such vigorous growth. From one viewpoint 

 this might appear to mean that where there is 

 mud the roots must find more nutrition, or from 

 another, that where water is more stagnant it 

 contains a greater proportion of nutritive mat- 

 ter than where there is current. I can only 

 argue the question from the standpoint of my 

 own experience and not from careful experi- 

 ment. At all events I have found sand to be the 

 most satisfactory medium for growing aquatic 

 plants and I have never found anything else 

 necessary or desirable. Where there is the 

 necessary sunlight to bring about the necessery 

 chemical interactions there is no foulness and 

 no unfavorable conditions. 



There can be no rule established by which 

 the number of fish that can be kept in a given 



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