26 



Aquatic JLitt 



beautifully colored specimens, he must 

 keep up the temperature, and keep it as 

 even as possible. Don't keep it so low 

 that you are flirting with disaster. 



Unnatural Tank Conditions. The 

 native haunt of the tropical fish differs 

 widely from even the most favorable 

 aquarium conditions, unrestricted move- 

 ment being in contrast with confinement 

 and monotony. Collectors have noted un- 

 usually brilliant colorations in wild speci- 

 mens, which disappears suddenly, or be- 

 comes inferior, under tank conditions. 

 The proverbial "large, roomy, well- 

 planted tank, maintained at an even tem- 

 perture of 72 degrees Fahrenheit," should 

 be provided. It is better to have three 

 good tanks than thirty small ones. 



Size of Aquarium. — It is interesting 

 to take a dozen young fishes, say Platy- 

 poecilus, and put half of them in a small 

 tank, the other half in a large one, con- 

 ditions being similar, and note the sur- 

 prising difference in the result. Not only 

 is growth more rapid, but color likewise 

 is improved by plenty of room. Save in 

 depth alone, a tank cannot be too large 

 for the well-being of the fishes. A Wis- 

 consin friend who boasted of having pro- 

 duced "dwarf Helleri" had yet to learn 

 that the ten-inch jars in which he reared 

 the young were inadequate. 



Acidity and Alkalinity. — These im- 

 portant f actors are too little discussed 

 among us. If the gentle (or "savage") 

 reader will evaporate a dozen pails of 

 water drawn from the tap, taking care 

 to use the same pail and retain the sedi- 

 ment, he will be astonished at the "thick 

 soup" which will result. This can be 

 tried on the back of a stove, or on a 

 steam radiator. Aquarium water evap- 

 orates rapidly under artificial heat, The 

 average aquarist adds water from the 

 tap. The water continues to evaporate, 

 while the substances in solution and in 



suspension remain. All water contains 

 such substances. The Shenango River, 

 in Pennsylvania, was called "Red Water" 

 by the Indians because of the substances 

 in suspension, probably from the Pyma- 

 tuning swamp. In many places the 

 Beaver and Ohio Rivers are acid, and 

 will turn litmus paper red. Northern 

 Wisconsin rivers show strong traces of 

 ore. In other localities salts from the soil, 

 or nitrates from agricultural districts, 

 are to be found in water. Steel mills, iron 

 furnaces, smelter plants, saw mills and 

 paper factories all add foreign substances 

 to the water. Sewage from cities, decay- 

 ing vegetation, surface drainage, and the 

 character of the stream bed and drainage 

 area play important parts. Water sup- 

 plied through municipal filtration plants 

 often contains considerable proportions 

 of chlorine and alum. It would be inter- 

 esting to procure a supply of litmus paper 

 from a dealer in biological supplies, and 

 to make the following experiments : Fill 

 two tanks, equal in size, and similarly 

 equipped, with plants and fishes. For 

 one use tap water and in the other place 

 water from a clear spring or stream. Test 

 occasionally by dipping a small piece of 

 litmus paper in the water, noting whether 

 it turns the paper red, blue or neutral. 

 Compare the effects on fishes, plants and 

 snails. 



.Selection. — Much has been said about 

 selection. But what, really, is selection ? 

 It is the proper combining of desirable 

 characters and the elimination of unfa- 

 vorable ones. Parental forms, food sup- 

 ply, proper tank conditions, plant life, 

 temperature, etc., all contribute toward 

 selection. Much remains to be done in 

 this respect. The question of inbreeding 

 plays a part here. But this, like Mark- 

 Twain's death, has been grossly evag- 

 gerated. Inbreeding will in time produce 

 baneful results, but the proper combining 



