26 NEW YORK AQUARIUM NATURE SERIES 



In the selection of plants the beginner, especially if he lives 

 in a large city, will probably have to depend largely upon the 

 dealer. As there are many kinds of plants suitable for the aqua- 

 rium there is a wide range of choice, according to the tastes of 

 the indiviiliial. 



The best species for aeration are those that will live entirely 

 submerged and which have (1) narrow, ribbon-like, or (2) 

 finely divided leaves. 



In the first class are the tapegrass {Vallis7ie7^ia) , arrow- 

 head {S(t(jittari(i) and pondweed (Potamogeton) ; and in the 

 second class, fanwort (Cabomba) , milfoil (Mifriophylhim) , 

 hornwort {Ceratophi/Unm) and waterweed (Anacharis) . 



The fanwort is the most difficult of the plants mentioned to 

 prow properly and is less satisfactory for aeration than many 

 others, yet it seems to be the form most usually sold by the 

 dealers. The others mentioned give little trouble, even to the 

 begin nei*. If a single species is purchased the beginner will 

 probably find Sagittaria or Anacharis the most satisfactory. 

 Two or three of these plants placed together in the tank give a 

 little diversity and make it more attractive than will a single 

 species. Nearly all of these plants will slip readily and the slips 

 will soon form their own roots if anchored to the bottom by a 

 pebble or a strip of lead. The tapegrass sends out runners, from 

 the joints of which young shoots arise. 



The plants must, of course, be provided with a sufficient 

 amount of light or they will not grow, as they are able to manu- 

 facture their food only in the presence of sunlight. For reasons 

 .^tated elsewhere the north window affords the best light for the 

 afjuarium. If the plants grow too luxuriantly they can readily 

 be trimmed. Some aciuarists prefer to trim off all the parts that 

 come to the surface, thus keeping the plants entirely submerged. 

 There is no doubt that such a method affords the maximum of 

 aeration, since the more the plants are submerged, the less is the 

 opportunity afforded for the escape of oxygen at the surface. 



However, many persons prefer the appearance of some 

 plants floating at the surface, and there can be no objection to 

 this so long as there is a sufficient amount submerged. Perhaps 

 the most picturesque, and therefore the most satisfactory, results 

 for the average person are obtained by providing at least two 

 kinds of plants, one like the arrowhead or pondweed with 

 broad leaves which are allowed to float at the surface, and the 

 other with finely divided leaves (milfoil, fanwort, etc.), kept 



