TERRARIA AND AQUA-TERRARIA 



of or screened with slate to conceal the back of the rockwork and earth in 

 which the plants are grown. 



Another form consists of a shallow open tank or aquarium having a 

 layer of soil covered with pebbles arranged to slope from a depth of 2 

 inches to within a half inch of the surface, screened by paint on the glass 

 to just above the soil level so that only the clean surface of pebbles is ex- 

 posed.. In these varying depths of water a great variety of aquatic and 

 semi-aquatic plants may be grown, sagittaria, ludwigia, fontinalis, anacharis 

 and cabomba to grow submerged; parrot's feather, water-hyacinth, salvinia, 

 triania and frog-bit on the surface, and semi-aquatic plants to grow one to 

 four feet above the surface. 



Fig. 238 gives a good idea of the beauty and the arrangement of a 

 receptacle of this kind, the plants shown being Maidenhair, Scirpus gracilis, 

 in the pot. Water-hyacinth and Parrot's feather on the surface and 

 Chinese and Montevidean Arrowheads and Umbrella plants growing above 

 the surface. This receptacle offers opportunities for tasteful and artistic 

 arrangement of plants and for keeping the lower forms of animal life, and 

 is usually installed in conservatories and greenhouses. 



Under proper conditions any of the following animals can be kept in 

 Terraria and Aqua-terraria. 



Batrachia. Frogs and Toads belong to the order Salientia or tail- 

 less Leapers, the Ranids or frogs, the Bufonidse or toads and the Hylidas 

 or tree toads. All are closely related, differing only in structural features 

 and habit. They have bony skeletons with projections on each side of 

 the vertebrae but no ribs, respiration being made by the throat and con- 

 sists of a continuous gulping to force air to the lungs. Almost the entire 

 cranium is taken up by the orbits, the brain cavity being very small. The 

 hind-legs are long and have webbed toes, the fore-legs are short and the 

 toes are without webs. In repose they sit nearly upright, a position ad- 

 mitting of instant movement which consists of long leaps, short jumps 

 and a crawling movement. They are oviparous and deposit spawn in 

 the spring and early summer months, which is fertilized by the male as it 

 is extruded by the female, the size of the ova being 1.75 to 2.6 millime- 

 ters, varying with the different species. The frog spawn receives a coat- 

 ing of albumenous substance as it passes down the oviduct, which rapidly 

 swells when the eggs enter the water and forms clusters of gelatinous 

 globules enclosing the eggs, also keeping them well apart and serving as 

 a protection. The spawn of the toad is enclosed in long strings or ropes 

 of the gelatinous substance, usually attached to aquatic plants. The eggs 

 develop as soon as fertilized, appearing as partly white and black spheres, 

 but as the embrio develops the entire egg enlarges, become black and 



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