Transactions of the London Horticultural Society. 483 



enable lis to judge whether it is probable, that a given species, which has been 

 the subject of actual experiment in one climate will succeed in another or not. 

 For this reason it has been thought advisable to go into the numerous minute 

 details included in this report. 



" The utmost which science can at ' present do, with reference to this 

 subject, is to judge from probability. We know that the more nearly the 

 climates of different countries approach each other, the greater the probability 

 that the species peculiar to those countries may be advantageously inter- 

 changed. But although this is a valuable guiding fact for general purposes, 

 it loses its value, or at least from the imperfection of our information appears 

 to lose it, when we descend to particulars. Because the climate of many 

 parts of the Himalaya mountains resembles that of England, it is probable 

 that the plants of the former will grow in the latter country, and experience 

 shows that this will really happen. But while such is the general fact, we 

 continually find exceptions to it, which nothing but actual experiment could 

 have led us to discover. For instance, the Deodar cedar appears hardy all 

 over England, but Abies Webbiana suffers so much from cold, that it is 

 doubtful whether it is likely to be of national importance in the midland and 

 northern counties, except in very favourable situations ; yet they are both 

 from the same tracts of country, and we could not have judged beforehand 

 that their constitution would be different. In like manner, Benthamia grows 

 on the second range of the Himalaya mountains, along with Berberis aristata, 

 asiatica, and others, and belongs to as hardy a family as they do. Yet Ben- 

 thamia has been almost everywhere killed by the frost, except in Devonshire, 

 Cornwall, and South Wales, and the others have as generally resisted it ; and 

 there is no apparent or theoretical difference in the nature of these plants to 

 account for the difference. Again, if we could judge beforehand of such 

 things, it would be said that the climate of Van Diemen's Land, especially 

 that of the southern face of the island, would yield plants suitable to Devon- 

 shire ; and such appears to be the fact with such species as Acacia stricta 

 and diffusa, Correa alba, Callistemon lanceolatus, Grevillea rosmarinifolia, 

 and some others ; but, on the other hand. Aster argophyllus, Pomaderris 

 elliptica and Veronica decussata, which is quite a mountain plant, were killed. 

 No one could have suspected that this would happen j it was necessary to 

 ascertain the fact experimentally. 



" There is no doubt, that if this kind of investigation were prosecuted with 

 sufficient care, and for a series of years, many plants not now reputed to be 

 hardy would be added to our out-door gardens. It will be seen that Hamelia 

 patens, a West Indian plant, lived for several years at Claremont ; Peganum 

 Harmala, a native of the hot plains of Syria, survived over last winter at 

 Cambridge, and it will be one of the objects of another part of this paper to 

 point out many similar cases. It is not, however, in a casual report of this 

 description that so extensive a subject can be properly treated ; all that is 

 now proposed, is to call attention to certain facts which appear to be 

 important. 



" AUSTRALIA. 



Acacia armata and verticillata survived the winter of 1836-7, but were now 

 killed at Sketty : in the spring of 1837 Mr. Dillwyn turned out some other 

 species which had been hardened in a cold frame, but they all died except 

 A. affinis and pubescens. A. affinis also survived at Glasgow ,• but though 

 on a wall it was killed to the ground. At Norwich a plant of A. dealbata 

 six inches in diameter at the ground was killed. In the Society's Garden 

 every species perished, some having been growing for several years without 

 suffering materially from winter cold. At Carclew A. stricta and affinis 

 proved more hardy than any others, although both were slightly injured; A. 

 Sophora was killed to the ground at this place in 1830-], but had subse- 

 quently attained the height of 15 or 16 feet ; after the frost the branches 

 required to be shortened, but there was no appearance of the stem being 



