162 



WINDOW GARDENING. 



be far more ■welcome to that class of our plant lovers who have often felt the dis- 

 appointment in their pot plants, many of the best of which, notwithstanding the 

 closest care, will show the yellow leaves and drop off, or the buds develop 

 but an imperfect blossom ; the fern case will prove to be their refuge in distress, 

 a never failing source of interest and amusement. 



Principles of the Fern Case. 

 Let us understand the principles of fern cases and the operation and life of 

 plants within. Those of j-ou who have observed plants under bell glasses or 



shades, have noticed that the moisture often collects so quickly inside as to actu- 

 ally obstruct or prevent the plant from being seen, and have wondered where this 

 moisture came from. 



The answer to this question is simple : " From the earth, the plants, by exha- 

 lation, i. e. vefjetable perspiration." But you ask again : " Why does it collect 

 so largely f " and we reply : "Simply because we confine it, and prevent its escape 

 and evaporation by making our ca-'^e airtight. If the case were ventilated, its tem- 

 perature would be moderated to correspond with tlie atmosphere of the sitting 



