240 THE WARDIAN CASE. 



plete change of the plants at any time. It is, there- 

 fore, not advisable to plant your case by rilling earth 

 directly into the table ; unless, indeed, you grow your 

 plants in pots, and plunge them in the soil, so that they 

 may be frequently renewed. The best plan is to have 

 zinc pans, one or more, according to the size of your 

 case, fitted closely to the inside of the case ; these 

 may be planted and changed from time to time. One 

 may have two sets, which can be renewed at a neigh- 

 boring green-house, and thus a perpetual display of floral 

 beauty may be obtained. 



However skilfully managed, a change of vegetation 

 in the case may now and then be desirable, and it is 

 easily effected by means of duplicate pots or pans. 



The frame of a Wardian case may be wood or metal ; 

 wood is least likely to be affected by sudden changes 

 of temperature ; metal is less liable to decay. 



The frame of our largest case is of bronze, but probably 

 the best metal is galvanized iron. 



The pans should be of zinc or galvanized iron. 



The advantages of the Wardian case may thus be 

 summed up : 



You may grow in them many plants which a single day 



