34 Instructions for the Scientific Expedition 



quisite, for this purpose, that the Botanist should be supplied with 

 bottles, jars, acetic acid and spirit. 



Attention should be especially directed to the distribution of re- 

 markable species in each country, regard being paid, in particular, to 

 the elevations at which they are found, and the soils which they seem 

 to prefer, where preference is observable. Connected with this topic 

 are the limits to which cultivated plants extend, and the circum- 

 stances under which they succeed or fail. In noting points of this 

 nature, facts concerning the commoner species will be interesting, 

 because they are so frequently neglected, and because of the evi- 

 dence as to climate which they may be expected to afford. In the 

 absence of this kind of knowledge, it is difficult for persons here to 

 judge correctly respecting the kind of plants it may be desirable to in- 

 troduce into another country. Should the causes of failure or of suc- 

 cess in the cultivation of particular plants be apparent, they ought 

 to be noted down. As an instance of the importance of this branch 

 of inquiry, the Vine at the Cape of Good Hope may be mentioned : 

 the bad quality of Cape wine, with the exception of that produced 

 at the farm of Constantia, is well known : can any physical cause be 

 assigned for this circumstance ? If exotic plants are commonly cul- 

 tivated with apparent success, they should receive particular notice ; 

 European Oaks, for example, are common about Cape Town, where 

 they are planted for their shade ; the species to which they belong, 

 and the effect of that climate upon their growth, and the quality of 

 their timber, are points deserving of attention. 



The original Flora of St. Helena should be fully investigated 

 and carefully distinguished from that which has been gradually 

 formed there by the introduction of numerous plants from various 

 countries. The association of plants in this island will be found 

 extremely curious, and the circumstances which enable species of 

 very different habits to flourish equally well in the same place, not- 

 withstanding their constitutional diversity, are deserving of particu- 

 lar attention. A very detailed catalogue should be formed of these 

 exotics, the degree in which they are affected by their new country 

 should be observed, and an attempt be made to discover the causes 

 which are favourable to the maintenance of so singularly mixed a 

 vegetation in so small an island. Such a catalogue, if well prepared, 

 may be expected to illustrate many difficult and important questions 

 which are connected with the relation borne by vegetation to cli- 

 mate. 



Both at St. Helena and Hobart Town, Tree Ferns will be found : 

 those in the former place have the stems destitute of external fibres 



