AQUARIUM. 



109 



larval forms of amphibia and some 

 species of fishes harmless to the other 

 animal inmates. 



Of the molluscs, those species which 

 feed on algae, the minute aquatic 

 plants, and decaying vegetation, in- 

 fusoria, rotifera and the general re- 

 fuse only should be introduced, not 

 those which prefer living and growing 

 plants. Experience has taught the 

 aquariist that five species of snails 

 and three species of mussels are best 

 for these purposes. They are the com- 

 mon forms of Planorbes, popularly 

 known as ram's horn, trumpet or flat 

 snails, and the large P, magnificus, or 

 Cape Fear river snail ; also the Vivi- 

 para, of which the Potomac and 

 Georgia snails, V. vivipurus and V. 

 gcorgiamis, and the introduced Jap- 

 anese snail, V. malleatus, are pre- 

 ferred ; and the so-called Trans- 

 parent African snail, L. auricularia. 

 Two or more kinds of these are advisable 

 as they all vary somewhat in pref- 

 erence of diet. 



Of the mussels the small Sphaerium 

 and the larger Lampsilus and Marga- 

 ritana longest survive and are most 

 effectual as scavengers. 



Tadpoles are also beneficial in con- 

 suming the sediment, food offal and 

 other organic substances, and of these 

 frog-tadpoles remain the longest in the 

 larval state. 



To consume worms, leeches, polyps 

 and animal parasites, small specimens 

 of sticklebacks and Indian paradise 

 fishes are used, which in a few days 

 will effectually remove these pests. 



In a freshwater aquarium of sav 

 twenty-five gallons of water, ten or 

 twelve snails, four small and two large 

 mussels and four or six tadpoles will 

 be sufficient. The sticklebacks and 

 paradise fishes need only be introduced 

 when the vermes and hydrozoa have 

 increased to such numbers as to be 

 objectionable or dangerous to the 

 other animals present. 



Saltwater aquarium scavengers are 

 not as efficient as those of freshwater ; 

 but the common forms of whelks and 

 limpets, bivalves, shrimps and small 

 crabs are used ; and, though some also 

 feed on the marine vegetation, thev 

 are fairly effective scavengers when the 



Reding of the other inmates is prop- 

 erly regulated. As marine plants are 

 introduced more to enhance the pic- 

 turesque appearance of the aquarium 

 than to serve as oxygenators, and as 

 the} do not thrive under the changed 

 conditions, their partial destruction by 

 these scavengers needs no serious con- 

 sideration. 



Enclosed Pond Aquaria. 



Greenhouses for the display and 

 propagation of tender and exotic 

 plants or the growing of fine fruit are 

 now so general that something new 

 ,and different may appeal to those 

 whose means will permit of its in- 

 dulgence. Attention is therefore di- 

 rected to the possibilities of a water 

 garden which would combine the 

 features of the aquarium and the pond, 

 to display the beauties of both the 

 fauna ami flora of the pond and river, 

 ,and also permit of the keeping of high- 

 ly interesting foreign forms of fishes 

 and plants that would probably not 

 survive in the aquarium or greenhouse 

 tank except under the care" of an ex- 

 perienced attendant. 



Veritable living pictures could be 

 produced that in ever-varying beauty 

 'and entertainment could not be equall- 

 ed by any other so limited expenditure 

 of money, thought and good taste, as 

 by this artistic arrangement of the 

 water garden- 



The suggestion originated with Mr. 

 \Ym. P. Seal and was published in a 

 bulletin of the U. S. Fish Commission ; 

 the idea being to construct a glass en- 

 closure similar to a green house, or 

 to make it a part or adjunct to a green- 

 house, thereby bringing the inhabit- 

 ants of the pond where their living 

 and loving may be observed and so 

 add another esthetic pleasure to our 

 existence. 



In carrying out this thought, the 

 aquaria would be built on the margin 

 of a pond or other water reservoir and 

 would consist of a series of glass-front 

 compartments extending back into the 

 pond, arranged at the front like an 

 aquarium, with a movable back screen, 

 so that any of the inhabitants may be 



