1837.] Extra-Tropical Plants within the Tropics. 231 



by the condensation on the sides of the bottle, and return of the 

 moisture, which evaporated during the heat of the day ; and that 

 plants, growing in mould so preserved, would live for months or years 

 without any additional supply of water. He was thence induced to 

 extend his experiments, and in the course of them ascertained that, so 

 protected, the most delicate plants, and from stations enjoying the 

 purest air, continued for years to thrive in the pre-eminently impure 

 atmosphere of London ; and that they remained nearly unaffected by 

 change of temperature, tropical and arctic plants, so isolated, growing 

 freely in the same case. 



The application of this last fact to the introduction of tropical plants 

 into England w 7 as too evident to be long overlooked. He says, " reflect- 

 ing on the causes of the failure attending such conveyance (of plants 

 on long voyages), arising chiefly from deficiency or redundancy of 

 water, from the spray of the sea, or from want of light in protecting 

 them from the spray, it was of course evident that my new method 

 offered a ready means of obviating all these difficulties, and in the 

 beginning of June 1833, I filled two cases with ferns, grasses, &c, and 

 sent them to Sidney." There they all arrived in safety, though the 

 glazed cases by which they were covered were not once, or only once, 

 opened on the voyage. " The English plants were removed, and the 

 cases refilled at Sidney in the month of February 1834, the thermo- 

 meter ranging between 90 and 100°." 



" In their passage to England they encountered very varying tem- 

 peratures ; the thermometer fell to 20° in rounding Cape Horn, and the 

 decks were covered a foot deep with snow. In crossing the line, the 

 thermometer rose to 120°, and fell to 40 o , on their arrival in the British 

 channel in the beginning of November, eight months after they were 

 enclosed. These plants were not once watered during their voyage, 

 received no additional protection by day or by night, and were taken 

 out at Loddiges' in the most healthy condition." Since then numerous 

 cases of plants have been sent to various tropical countries, and others 

 returned with equal success. It is now the practice to send annually 

 numerous cases of plants so protected from the Calcutta botanic gar- 

 den to England, the glass cases of which, are not once opened during 

 the voyage; the only precaution required, being to place them in such 

 a situation as to afford them the greatest quantity of light. 



My object in recapitulating so much of this paper, is to show the 

 application of it to the determination of the value of my suggestions 

 for acclimating plants. In the hot houses of England, where the tem- 

 perature is kept up to the tropical standard, the seeds of fruit and 

 timber trees might be germinated, and the young plants sent to this 

 country for introduction, along with others (for the sake of comparison) 

 germinated in the usual way, 



