WITH THE MICROSCOPE. 151 



crustacea, starfishes, echini, wandering annelids, waterworn nodules 

 for investing social ascidians, such as the Botryllidae, or multivalve 

 mollusks, such as chitons. Loose stones and large boulders should be 

 turned over, as many crustaceans and annelids take refuge beneath 

 them. Large tufts of corallina and other sea weeds should be gathered 

 from the edges of pools near low water, and placed in a jar of water 

 as they harbour Entomostraca, Pycnogonidae, Lucernaria and other 

 zoophytic forms. Outstanding rocks only uncovered at the lowest 

 spring tides, and then usually only approachable by boat, should be 

 visited in the hope of finding the only British representatives of the 

 stony corals. Beyond such points, the sea bottom must be ransacked 

 by means of dredge and draghook. 



247. Vivaria and Aquaria. Many of the lower animals and 

 plants may be kept living in glass cases and glass jars, and will 

 grow and multiply in confinement. Frogs, newts, lizards, many 

 mollusks, insects and worms, air-breathing and aquatic, will live 

 for a length of time in confinement, and some, flourish. 



Vivaria are now made of various forms and sizes, and many of 

 them are most ornamental. The student may easily arrange such 

 for himself for a few shillings, and may keep a number of objects of 

 the utmost interest which will provide him with endless amusement 

 and constant work. 



Cases for breeding insects and keeping them alive may now be 

 obtained of many naturalists. 



Frogs, toads, and newts may be kept in glass cases to the interior 

 of which air has access through wire gauze. At the lower part 

 should be some water which may be placed in a saucer or basin with 

 shelving sides. This may be made ornamental and adapted for 

 plants if desired. 



Fresh water aquaria may readily be formed by inverting propa- 

 gating bell glasses, carefully selected as to shape, in a turned wooden 

 stand or in fern dishes which have been filled with earth or sand. 

 The bottom of the bell-glass should be filled with rich black peat 

 earth, worked into a paste, and this should be covered with a thick 

 layer of fine well-washed shingle. Roots of vallisneria, anacharis, 

 or chara may be then planted in the earth and the vessel carefully 

 filled up with water. After the water first introduced has become quite 

 clear a few fresh-water mollusks should be added to keep down the 

 growth of conferva. Those species which feed rather upon decayed 

 vegetable matter than upon the plants themselves should be selected, 

 such for instance as Planorbis corneus or carinatus, Paludina 

 vivipara, or Amphibia glutinosa. When the water has cleared and 

 the plants are in good condition, which may be known by their 



