14G 



this high temperature of the soil is something unusual in our 

 country, yet similar circumstances occur very commonly in 

 certain tropical regions. On the coast of the island Lantao 

 (China) in August at half-past three P.M., I ascertained the 

 water of some rice fields to be 36 R. : evidently the adjacent 

 sand, which was completely clothed with plants, was still 

 higher, for towards mid-day I had observed the black sides of 

 the vessel to be heated to 49-2 R. 



M. Goeppert has given as an introduction to this work some 

 very complete historical notices of the occurrence of plants in 

 hot sources and in unusually warm soils, which will be of great 

 service to future writers on this subject. 



M. Zuccarini in his monograph of the Cactece* has treated 

 very fully of their geographical distribution. Cactus plants 

 have been observed in the New World from 49 north lat. to 

 the southernmost parts of Chili, and it is to be presumed that 

 they go as far south in the southern hemisphere as they ascend 

 northwards in the northern. Their vertical distribution goes 

 through all regions, from the hot plains of the tropics to the 

 neighbourhood of eternal snow. Some species of this family 

 were collected on the west side of North America in 44 45 

 lat. at great heights, and Nuttall has discovered several Cacteae 

 in similar latitudes on the high mountains in the Mandan di- 

 strict. Opuntiae have been observed up to 41 lat. on the east 

 side of North America. " So extensive a distribution of the 

 family/ 5 says M. Zuccarini, " leads us naturally to expect a 

 great variety in the peculiar habitats of the different species. 

 But it must be observed, that with the exception of cultivated 

 Opuntice and Cerei, all the other species are limited in their 

 occurrence to small districts, and therefore statements like 

 that of Meyen of the occurrence of the Mexican Cereus senilis 

 on the Andes of Chili are probably founded on errors arising 

 from want of comparison." I am glad to be able to give some 

 explanation on this point. I have not seen the Cereus senilis 

 on the Andes of Chili, I do not understand therefore how the 

 author can make such a remarkable statement ; but I saw a 

 Cereus in the Cordilleras of southern Peru, which resembled 

 in habit the Cereus senilis of our hot-houses ; nay, I did not 



* Denkschriften der mathematisch-physikalischen Klasse der kbnigl. 

 Acad. der Wissenschaften zu Munchen, vol. ii. 1837. 



