102 PLANTS FOR TUB 



arc improperly termed, will not do for our tanks ; many 

 will cither not grow at all or will soil the water when 

 so doing and render it unlit for the habitance of other 

 species and animals. 



As a general rule, let it be borne in mind that the 

 green algcc or, as botanists have named them, Chloro- 

 sperms, are always the best for the Aquarium, being the 

 cleanest, best aerators, and, at the same time, easiest ob- 

 tained and replaced when anything happens to require a 

 change. Let all the olive varieties — the fuci, so common 

 covering every stone and rock on our shores — be dis- 

 carded as worse than useless, as they give off a mu- 

 cous substance which renders the water of the tank 

 obscure and decomposing, soon turning it foul, so that 

 it destroys other tenderer species. I have tried many 

 times, and many of the olive species of all sizes in vain ; 

 even when beginning with young plants, it has been the 

 same in the cud when they have become old enough to 

 be despotic, for they then have asserted their powers 

 as destroyers, and killed my other plants. Some of them 

 would look very well in a tank, as the Fucus vcsiculosus 

 and F. scrratus, their deep olive fronds contrasting with 

 the lighter colored Ulva and Ddesscria ; but, unfortunately, 

 they cannot be introduced with any safety. Their fronds, 

 however, on the sea-shore serve as a refuge for a multi- 

 tude of strange forms, and, therefore, present a fine hunt- 

 ing-ground for the naturalist, where he may nearly al- 

 ways be sure of plentiful sport. 



The only plants I can, with any confidence, recommend 

 to beo-iuners are the Ulva lutissima, U. linza and Enter- 



