VIVARIUMLICHENS. 



149 



but can be raised at will ; it is covered with a round piece of 

 flat glass. On this stands a saucer of well moistened clay 

 stuck round the edge 

 with such leaves as the 

 insects feed on. In the 

 centre of this saucer is a 

 small vase rilled daily 

 with fresh flowers and 

 grasses for the butter- 

 flies. 



It is easy in this ap- 

 paratus to raise moths, 

 butterflies, and other 

 winged insects, such as 

 saw-flies and the like, 

 from the egg; and the 

 many changes may be 

 watched through the 

 glass, from the emerg- 

 ence of the caterpillar 

 from the egg to the exit 

 of the imago from the 

 pupa case. 



LICHENS. These in- 

 teresting vegetable pro- 

 ductions require but an 

 old knife and a few pill- 

 boxes for their collec- 

 tion, with occasionally a hammer and chisel. The purer 

 the atmosphere of the district the greater variety to be 

 found, while in a smoky and gas - polluted atmosphere 

 they are either not found at all, or only to be met with 

 in the gonidial state, when they may be easily mistaken 

 for protophytal algae. Lichens are to be found growing 



FIG. 135. 



