SELAQINELLA. 231 



takes place more or less when it is in contact with stagnant 

 water, an outlet at the bottom of the case should be care- 

 fully provided, by which all the free water at least, which 

 drains through after the soil has been irrigated, may be 

 removed at it accumulates. 



As to aspect, the northern is decidedly the best, princi- 

 pally for the reason that in such a situation the sun has 

 less influence on the temperature of the interior of the 

 case ; and an extreme degree of confined heat would be 

 anything but favourable to these plants. 



The appearance of the case, would, no doubt, be improved 

 by covering the soil entirely with living Sphagnum moss, 

 which, if neatly packed on the surface, with the tops of its 

 stems uppermost, would continue to grow. Most of the 

 species of Club-moss would prefer to grow amongst the 

 Sphagnum, which, to prevent its being drawn up and 

 smothering the plants, should be neatly clipped down 

 occasionally with a pair of scissors. 



The interest of such a collection, so far as their appear- 

 ance is concerned, would depend of course upon the taste 

 with which the rockwork was designed and executed, and 

 the plants distributed about it ; but whatever the result as 

 a matter of taste, the study of the living plant might be 



