By Mr. D. Beaton. 



461 



tinent ; and these are more particularly met with from the mouth 

 of the great La Plata to the Mexican gulph. Mackenzie the col- 

 lector sent out by Mr. Harris and Mr. Lowe of Clapton, found 

 Melocactus communis, M. amcenus, M. meonacanthus, Mammillaria 

 glomerata, and some fine Cereuses and Opuntias, growing down to 

 the water's edge in the hottest part of the globe ; which, according 

 to Humboldt, is from Cumana to La Guayra, and the Gulf of Ma- 

 racaybo. Along the same coast he met with those species in abun- 

 dance in open arid places ; and he tells us that the plants seem to 

 enjoy the reflection of the sun's rays from a naked soil, in addition 

 to the scorching heat of the atmosphere. From this region of ex- 

 cessive and perpetual heat, up to the limits of perpetual snow, or 

 nearly so, some species of Cactus or Opuntia are to be met with, at 

 every degree of elevation. In the latitudes of the periodical rains, 

 the Cacti are deluged for three, four, or five months at a time, while 

 they are completely dry for the rest of the year. They may be 

 said to enjoy a perpetual spring in some localities, such as, for ex- 

 ample, in the vallies of the " tierra templada" in Mexico, or in the 

 higher vallies of New Grenada, and in the neighbourhood of Quito, 

 and other places of similar temperature ; and I believe a few Ce- 

 reuses are found in that part of the Peruvian coast where rain is 

 unknown. We have some seedlings here, received from the Hon. 

 and Rev. W. Herbert, and raised from seeds gathered by Mr. 

 Pentland on the Andes of Cusco 13° S. lat. at an elevation of 

 nearly 15,000 feet, where the mean temperature is 46°, also from 

 the Andes of Bolivia, altitude 14,600 feet ; and still farther south 

 in lat. 19° we have from the same source Cacti from a mean tem- 

 perature of 45°. 



From this hurried glance at the physical history of the Cacti, 

 and comparing them with other genera of equal, or even a less 

 geographical range, we might a priori be led to think it impossible 

 to grow all these plants in one house with any degree of success; 

 yet such is frequently the case. It is true that the Alpine Mam- 



VOL ii. 2nd. series. 3 O 



