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APPENDIX A. 
this great variety of living forms, this house contains a large and fine collection 
of Lepidodendra, Calamites, See. &c., which, when compared with their recent 
types, the Lycopodia and Equiseta, are truly — 
“ of aspect that appears 
Beyond the range of vegetative power.” 
Such are some of the results obtained in a temperate climate, and there can- 
not, I think, he a doubt that in tropical countries the application of this same 
plan might be equally striking and beneficial. 
In ordinary horticulture a great deal is effected by closely imitating the na- 
tural conditions of plants. Thus my friend Dr. Royle, who has paid especial 
attention to this subject, informed me that there were certain plants in his gar- 
den at Saharunpore, which he could only keep alive by surrounding them with 
small trees and shrubs, so as to give them a moister atmosphere than they could 
otherwise have obtained ; and he mentions in his beautiful work, the ‘ Illustra- 
tions of the Flora and Fauna of the Himalayas,’ a striking example of this 
kind. — “ To show the effects of protection and culture, Xanthochymus dulcis 
may be adduced as a remarkable instance. This tree, which is found only in 
the southern parts of India, and which would not live in the more exposed cli- 
mate of Saharunpore, exists as a large tree in the garden of the King of 
Delhi ; but here, surrounded by the numerous buildings within the lofty palace 
wall, in the midst of almost a forest of trees, with perpetual irrigation from a 
branch of the canal which flows through the garden, an artificial climate is 
produced, which enables a plant even so sensitive of cold as one of the Gutii- 
ferce to flourish in the open air of Delhi, where it is highly prized, and reported 
to have milk thrown over its roots, as well as its fruit protected from plunder 
by a guard of soldiers.” 
Supposing ourselves in a hot and dry country, let us see what may be done 
by surrounding our plants with glass, and lowering the temperature, if re- 
quired, by means of the evaporation of water from the external surface. We 
shall be enabled in this manner, as with the wand of a magician, to turn a 
desert into a paradise. The probable results cannot be better described than 
by copying the beautiful description of the palm-groves given us by Desfon- 
taines, in his ‘ Flora Atlantica,’ 
“ Palmeta radiis solis impervia, umbram in regione calidissima hospitalem 
incolis, viatoribus, aeque ac animantibus ministrant. Eorum denso sub tegmine 
absque ordine crescunt aurantia, limones, punicse, oleae, amygdali, vites, quae 
cursu geniculato saepe truncos palmarum scandunt. Has omnes fructus suavis- 
simos, licet obumbratae ferunt ; ibique mira florum et fructuum varietate, pas- 
cuntur oculi ; simulque festivis avium cantilenis, quas umbra, aquae, victus 
illiciunt, recreantur aures.”^ 
* These palm groves, being impervious to the sun’s rays, afford a hospitable shade both to man 
and other animals in a region which would otherwise be intolerable from the intense heat. And 
under this shelter the orange, the lemon, the pomegranate, the olive, the almond, and the vine, grow 
