230 Scientific Intelligence. [Sept. 



VI. On the Naturalization of tender Exotics. By Mr. Murray. 



Dr. MaccuUoch has given to the Caledonian Horticultural 

 Society a paper on the Naturalization of tender Exotics, which 

 has been pubhshed in their " Memoirs," and crowned with their 

 gold medal. 



I can discover nothing in this paper which had not been 

 before treated of by Baron de Humboldt, and is to be found in 

 his " Personal Narrative." It proceeds upon the assumption that 

 plants may, by a gradual transition, be made to endure finally a 

 more rigorous clime, and that tropical vegetation may ultimately 

 luxuriate and be naturalized in climates the most remote from 

 the confines of the torrid zone, 



Guernsey is singled out as an appropriate nursery for this 

 intermediate transplantation, and it is suggested that the seeds of 

 such tropical plants as have been transposed to this island will 

 give birth to a race more hardy than their primogenitors. But 

 the question will always return, what is there peculiar in the 

 atmosphere of Guernsey, or other insular tracts of country, 

 which there imparts to the exotics of a torrid clime all the "pomp 

 and circumstance " of tropical vegetation ? Dr. MaccuUoch 

 adverts to the wiiformityzoi the climate, and this seems to me to 

 be the grand cause why we witness in Guernsey the luxuriance 

 of exotics, which we in vain attempt to recognize in lower lati- 

 tudes. Of the cause of this uniformity we are not informed, and 

 it may, perhaps, not be deemed irrelevant if I attempt to account 

 for it. (^See the next notice.) 



In the Memoirs of the Caledonian Horticultural Society, a 

 facetious writer proposes to make the cloudberry leave its alpine 

 seat, and hop, step by step, into the plam below. In the former 

 case it is more than probable that the transition from a uniform 

 to a very variable clime would operate as fatally as that from 

 high increments of temperature to frigid media ; so in the latter 

 instance there is more to be taken into the account than a mere 

 transit from an alpine elevation to the level of the sea in reference 

 to temperature. It may not only be more uniform, but there is 

 less density, and in point of hydrometric relations a greater 

 siccity : while the electrical state of the medium is very different. 



That a gradual and well managed introduction will accomplish 

 much, striking analogies would lead us to conclude, but it is 

 evident a great deal is to be taken into calculation, and that we 

 are not to feel disappointed if our endeavours are sometimes 

 bafHed. 



At p. 77 of the Edinburgh Philosophical Journal, No. V. (for 

 July) we have a remarkable evidence of what may be done in 

 this way by the detail which Mr. Macnab there gives us of a 

 suspended plant of Ficus Australis, which had grovsm uithout 

 earth for eight months. Mr. Macnab also pointed out to me in 

 the same stove a species of Solandria which bids fair to yield a 



