OP THE ACCLIMATATION GP PLANTS. 



The constitution of plants, however various, is always adapted to the climatic 

 changes and circumstances on which they are found. If their habitat be exposed 

 to severe frost, they are fortified against its destructive, effects ; if to the 

 parching heat of a tropical sun, they are equally fitted to bear and thrive under 

 it. All the intermediate latitudes, which are more or less temperate, have each 

 their peculiar tribes of vegetation. 



The intensity of cold in the high latitudes, and the torrid heat of the low, 

 divide vegetation into two constitutionally separate parts ; and though the 

 natives of the frigid zone cannot long survive in tropical Warmth, yet there are 

 many tropical plants which are successfully cultivated in countries far to the 

 north, even in Siberia. But this is not owing to their constitutional hardihood, 

 but to the circumstance of their coming soon to perfection, that is in a summer 

 of three months' duration. This description of plants are called annuals, because 

 they are sown and ripen their seeds in the course of one summer. A great 

 majority of the plants which embellish our flower-gardens are natives of warm 

 latitudes, and though the temperature of our summers is sufficient for them, they 

 are destroyed by the least visitation of frost. 



There is another class of tropical plants which are perennials ; the roots of 

 these survive our winters, but their stems are invariably killed down by frost, 

 and there are a few both herbs and shrubs, which, though natives of the torrid 

 zone, are nevertheless proof against our severest frost. Of these, we may only 

 instance the common white jasmine, which is a native of India. 



The desire to naturalise (like the well-known jasmine) the many beautiful 

 flowering shrubs and trees natives of warmer skies, is natural to every lover of 

 plants in this and other northern countries. In furtherance of this object, many 

 experiments have been made to ascertain whether the denizens of warmer climes 

 may be enured to the chilly air and frost of our northern latitudes. Some 

 botanists have imagined that tender plants have a predisposition or constitutional 

 mutability by which, whatever may be the temperature of the station they are 

 placed in, they will accommodate themselves thereto. But no rule of practice 

 has been founded on this idea ; on the contrary, nothing but the actual and 

 gradual exposure of the plants we wish to acclimatize, can be a certain test of 

 their ability to bear the rigours of a colder climate. By such trials the Aucuba 

 Japonica was found to be perfectly hardy. Many South American, Chinese, 

 and Australian plants have been found to be half-hardy ; and before this last 

 winter (1837-8) many curious kinds from the above-mentioned countries which 

 were supposed to be hardy are now dead or nearly so ; the roots only of many of 

 thern remain unhurt. But the frost of last winter was uncommonly severe, many 

 of our hardiest natives having suffered. 



That the texture and consequent susceptibilities of plants are varied according 

 to the aspect, or moisture, or poverty of the soil, is perfectly obvious. The 

 growth is retarded by cold, drought, and by a want of sufficient nourishment ; 



