unsightlv, and the pebbles and stones are periodi- 

 cally boiled and scoured. In nature plants will 

 not be found associated with gravel and rocks. 

 These mean rapid currents, which wash away all 

 sedimentary deposit, the food of the plants, and 

 cause such a continual shifting that few plants 

 will grow under such conditions and these do not 

 thrive in the quiet waters of the aquarium. Only 

 sand and sedimentary deposit will be found in 

 the quieter waters where plant life abounds. Of 

 course, on the shores of tidal waters and even of 

 ponds there will be found bare spots where gravel 

 and stones will show, and in the aquarium such 

 arrangement would be effective. But what is par- 

 ticularly to be avoided is any attempt to arrange 

 plants in symmetrical order as a garden or 

 orchard would be planted. The endeavor should 

 be to imitate the careless and graceful profusion 

 of nature. 



To get the best results in the operation of an 

 aquarium proper conditions of light and tem- 

 perature are required, and after that, time is an 

 important factor. It may require weeks and even 

 months to get an aquarium into an ideal condi- 

 tion. When a properly conditioned aquarium as- 

 sumes the crystal clearness, and develoi)S a 

 growth of algae, approximating that of an old 

 spring, in addition to a luxuriant growth of the 

 larser plants, it will have attained an ideal con- 

 dition. W. P. Seal. 



One of the most difficult fish enemies to combat is the fish 

 louse," of which the above shows enlarged ventral and dorsal 

 views. The figure in center shows natural size. They fasten 

 themselves firmly on the body or fins of the fish and gradu- 

 ally suck the life fluids from their unwilling host. Being 

 nearly transparent, they are difficult to see, and can only be 

 removed by picking off", since any chemical strong enough 

 to kill them will also kill the fish. 



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