1836.] Observations on the Flora of Courtallum. 



So 



Influenced by views similar to those so admirably ex- 

 pressed in the preceding extract, I shall proceed to examine 

 in succession the principal natural orders of which I have 

 specimens from this station. In these notes I follow the 

 natural system, not only on account of the facilities which it 

 offers to myself, but in the expectation of being able to eluci- 

 date by numerous examples the various benefits which the 

 botanical student derives, from the now nearly general 

 adoption of that method. 



Through its means we can often trace affinities of soil and 

 climate, in circumstances the least to be expected, and 

 equally diversities where altogether unlooked for. The exa- 

 mination of a dried collection of plants, will often enable the 

 botanist, without any collateral information, to declare the 

 existence in a country of local causes exerting sufficient 

 force, in modifying the climate, to counteract the effect of 

 geographical situation. For example, many families of plants 

 are only found within the tropics, or in the warmer regions 

 on their confines : while many others are rarely found to ex- 

 tend beyond the temperate zone. Specimens of both de- 

 scriptions being found in a local collection indicate as clearly, 

 to the botanist, as if he had himself visited the region, that 

 the plains experienced a tropical climate, while the higher 

 hills enjoyed a temperate one. The first and second orders 

 of the following arrangement, (RanunculaceaB and Dil- 

 lenaceae) afford illustrations of these positions. Of Ranuncu- 

 laceae, an extra tropical order, Professor Decandolle de- 

 scribes 505 known species, 119 of which are European 5 74 

 North American, only 19 Indian. Of the 19 referred to 

 India, only three or four are found on the plains, the rest are 

 Alpine, mostly from Nepaul and the Neilgherries. The 

 number of Indian species has been greatly augmented since 

 the publication of his work, but, the additions only tend to 

 confirm the general rule, since they are nearly all from the 

 Himalayas, while 10 of 13 Peninsular species are limited to 

 the Neilgherries, and two of the remaining three found on 

 them. Of Dillenaceee, on the other hand, 21 of 96 species 

 are Indian, and most of the others are found either within 



