THE SCIENTIFIC MANAGEMENT OF THE 

 AQUARIUM 



W. P. SEAL 

 (Continued from last issue.) 



NOTE: The word "protococens" on page 68 

 in our previous issue should have been spelled 

 "Protococcus." 



There is no advantage in absorption of 

 air from the surface. In fact it is more likely 

 that vitiated or poisoned air will be thus intro- 

 duced as water is a great absorbent of impurities 

 from the atmosphere. A close fitting glass 

 cover to prevent this and to keep out dust will 

 be found to be a great advantage, where there 

 is the necessary sunshine and efficient oxygena- 

 tion. As the oxygen which is liberated in excess 

 of what the water will hold in suspension will 

 collect between the surface of the water and 

 glass there will always be a highly oxygenated 

 atmosphere above the water instead of one of 

 possibly vitiated or poisoned air. The water will 

 also evaporate and collect on the glass, constant- 

 ly dripping back charged with oxygen, thus ef- 

 fecting further eliicient oxygenation Used in 

 this way, if properly stocked, the ordinary fish 

 globe is as etficient as any other form of vessel. 



There has always been much discussion as 

 to the medium in which the plants should be 

 rooted, some using pebbles, some sand or the 

 two mixed, while by some clay and soils of 

 various kinds are preferred. Notwithstanding 

 fhe published results of experiments made in 

 growing aquatic plants, I have, as a result of 

 my own experiences and observation, for a long 

 time doubted the necessity of using anything 

 except sand for this purpose. It has seemed 

 to me that the roots of aquatic plants are useful 

 only in anchoring them and not as the means of 

 nutrition. The growing tips of cabomba cut 

 off from long stalks will, if weighted and drop- 

 ped to the bottom, begin to grow before roots 

 are throv/n out, evidently taking nourishment 

 directly from the water through the leaves and 

 stalks. Ceratophyllum and Utricularia have no 

 roots and yet grow luxuriantly if given the 



72 



