52 TOWN AND WINDOW GARDENING 



devised a respirator for human beings on the charcoal 

 principle, for use in districts smitten with cholera or 

 yellow fever. 



What Plants suffer least from Fog ? 



This is such an important question for town people 

 that I have given it a separate heading. Here is the 

 answer : Ferns and bulbous plants. The latter have 

 but a short reign ere they die off, so that we must put 

 down Ferns as the Londoners' greatest stand-by. Con- 

 sidering the tender and delicate nature of their foliage, 

 this is one of the things we should deem a miracle if we 

 were not used to it, but the frailty of the Fern is only in 

 appearance. 



Professor Oliver, in a Report to the Scientific Com- 

 mittee of the Royal Horticultural Society, says, " At Kew 

 Gardens I have examined the various Fern-houses after 

 spells of severe fog, when the collections of stove plants 

 in adjacent houses were completely disfigured from this 

 cause, without remarking any damage to the Ferns to 

 speak of." 



How is this ? Ferns are shade-loving plants, so that 

 darkness, such a terrible foe to most plants, is to them 

 comparatively harmless. Other things being equal, the 

 more greedy a plant is of sunlight, the more will it suffer 

 when its illumination is reduced. There is another point 

 that tells in favour of the Fern. During the sunless months 

 of autumn and early winter the vitality of most flowering 

 plants is lowered, which renders them unfit to bear a 

 strain — they are " run down," and, like ourselves in the 

 same circumstances, liable to " catch " anything, and go 

 under. Ferns, on the other hand, meet the enemy and 

 battle with it in good condition ; no doubt their excellent 

 constitutions are largely inherited from early forefathers 

 who lived in an age that was far too rough for flowers ; 

 they were giants in those days. 



