147 



even see this quite close in my rapid journey, much less ex- 

 amine it attentively, so that it may very likely be some other 

 species ; yet this must not be asserted too hastily, for the re- 

 lations of climate in which Cereus senilis occurs in Mexico and 

 those of southern Peru, at the height in which I found this 

 plant, are exceedingly similar. Moreover, M. Lehmann has 

 described a Cereus bradypus from Brazil, which M. Pfeiffer 

 considers to be synonymous with C. senilis, Haw. These 

 statements however must be founded on actual comparisons, 

 and even then it would be incorrect to ascribe generally a very 

 restricted occurrence to the Cactece. Besides, plants of very 

 limited stations allow rarely of wide artificial distribution, 

 which we however find to be the case with the Cactece. 



ee The Cactece seem to be pretty indifferent as to the nature 

 of the soil, for the individual species are found without di- 

 stinction on limestone, sandstone, primary formations, and on 

 strata which have been altered by volcanic action." They are 

 even frequently found on the sea-shore, especially Cerei and 

 Opuntice ; but I cannot agree with the author, that all Cactece, 

 with the exception of the Peireskice, require an open sunny 

 situation. All those Cactece which require a permanent warm 

 and moist climate, and frequently occur parasitical, i. e. on 

 the bark of other trees, as the Epiphyllece according to Her- 

 mann's statement, and also many species of Rhipsalis, vege- 

 tate most luxuriantly in the shade ; the Peireskiae on the con- 

 trary that I met with in their native country stood quite ex- 

 posed to the sun. M. Zuccarini further enumerates a series of 

 observations, whence it results, that the climate which suits the 

 various Cactece passes from the heat of tropical countries to the 

 temperature of the colder temperate zone ; that therefore it is 

 impossible in their cultivation to keep all the species, in ac- 

 cordance with nature, under similar external influences, al- 

 though most species allow of considerable latitude. M. v. Kar- 

 winski has given the natural habitats and heights at which 

 they occur, for a great number of Mexican Cactece, and has 

 published them in this work. The Echinocactus macrodiscus 

 occurs there at an altitude of from 9 to 10,000 feet. 



In the consideration of the distribution of the Cactece, not 

 American, M. Zuccarini inclines to the view that Rhipsalis 

 Cassytha is indigenous to the Isle of France and Bourbon, and 



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