Cultivating Plants in Walls. 59 



chisel, sufficiently wide to admit the root easily, and penetrat- 

 ing so far as to reach the looser mortar of the interior. After 

 this it is secured by means of fresh lime or clay, to guard against 

 accidents until it has taken root ; nor are the roots of such 

 plants long in finding means of penetrating the firmest and 

 best laid pieces of masonry ; having thus succeeded in a brick 

 wall, for example, where the cement was so stony that the 

 bricks gave way to the chisel in preference to the lime. The 

 power of the Tussilago fragrans, in this respect, is quite 

 extraordinary, and even proceeds at times to more than 

 hazard, to destruction ; since I have seen one case where 

 such a plant had found its way from a garden, through and 

 through the wall, in fifty places and more, sending out an off- 

 spring at every joint, on both sides, and ultimately dislocating 

 a stone wall of three feet in thickness, so as to be on the point 

 of oversetting it. 



It is in this manner that I have most frequently sown the 

 seeds both of annuals and perennials, and with general success ; 

 and I need not dwell on that part of the subject, as I also 

 need not prolong these remarks on the mode of conducting 

 this sort of cultivation. I may only add, that in dry seasons 

 or peculiar circumstances, it would be expedient to keep the 

 plant moist until it is rooted ; while it will not be difficult to 

 find expedients for this purpose by means of water and strings, 

 or otherwise. 



Let me now make a few remarks on the following catalogue, 

 as I am desirous to restrain this paper within as moderate 

 bounds as possible. It is not solely a catalogue of our native 

 plants, as far as they will grow in such situations, but, such as 

 it is, I have introduced none that I have not actually seen 

 thus growing, through the length of time in which I have paid 

 attention to this subjeet. If it also contains every native 

 plant that I myself have so observed, though I have no doubt 

 that there are many more, and if I intended at first so to limit 

 it, I could not do this ; because there were some important 

 plants capable of such treatment, and belonging to no native 

 genus, and which therefore could not else have been pointed 

 out. And this plan I have followed wherever the genus was 

 native ; that is, I have introduced, under the genus, only the 



