212 Dr. Mac Culloch on the 



the intended purpose ; and if it shall be objected that some are 

 already hardy in England, it must be remembered that part of the 

 object was to show the great increase of vigour gained by exclu- 

 sion and climate together, as in the case, for example, of the 

 Veronica decussata, which grows about the little gardens of the 

 cottagers, to the size and appearance of a common gooseberry- 

 bush. 



As to the effect of exclusion, and in a sort of herbaceous plant, 

 if I named the Yucca before, I might have remarked that the 

 filamentosa and the aloides are equally vigorous, and that, on the 

 first plant of the tenderer of these species the effect of exclusion 

 was to cause it to flower in the first year, after having been many 

 years in the greenhouse without showing the least inclination to 

 blossom. If the American aloe does not choose to flower very 

 often, it does nevertheless flower out of doors, and propagates 

 itself with great vigour, even in stone walls. 



Among herbaceous plants reputed tender in various degrees, 

 but here flowering vigorously and freely out of doors, I may enume- 

 rate the following, without any anxiety to distinguish such as have 

 been occasionally treated as hardy by gardeners in England. Liko 

 the shrubs already enumerated, they may lead to further trials 

 among ourselves. 



Every Mesembryanthemum, without exception, having been 

 found hardy, I need not name the species : and the same 

 has been found true of a great number of the Cactus, of 

 which, however, I need only name the hexangularis, the formo- 

 sissima, the common caterpillar, and the prickly pear. Of allied 

 plants, the Crassula coccinea has also proved hardy. An Echium 

 sent from a London hothouse, whose specific name I could not at 

 the moment discover, and long kept in the house, proved perfectly 

 hardy: offering one proof, among a thousand others that might 

 be adduced, of the mistakes committed on this subject, which have 

 so long contributed to rob us of ornaments that ought to have been 

 now flourishing in our gardens. This, in fact, is a leading error 

 among all gardeners. Regulated merely by habit, or else by 

 geography as to new plants, it is not sufficiently often inquired 



