AD FLOBAM INDICAM. 3 



conducted with every precaution, under every advantage of books, 

 tlie best-named Herbaria in Europe, and the constant revision and 

 assistance of several distinguished botanists at Kew, so many 

 mistakes must occur, that it is with great diffidence that we pub- 

 lish our first crude results in the present incomplete form. On 

 the other hand, it is obvious that the collation of such Herbaria 

 and books must yield at every stage of its progress a vast number 

 of data regarding the distribution, structure, affiaiities, and nomen- 

 clature of Indian plants, which no other circumstances could elicit, 

 and which no more detailed or critical investigations can after- 

 wards subvert ; and it is these which will give the chief, if not the 

 whole, value to our sketches. 



These data, if systematically collected and arranged, will assume 

 the shape of a tolerably complete catalogue raisonne of the Plora 

 of India, w^hich will be most full and accurate as regards the 

 number and distribution of the species, and least so as regards 

 references and synonyms, and the limits of critical species*. In 

 the process of collecting them, we should in many cases be enabled 

 to form more correct estimates of the relative value of those mor- 

 phological differences upon which natural orders and genera are 

 founded, than we could by a closer study of fewer species or 

 genera; and we should be enabled to appreciate the effects of 

 exposure, elevation, temperature, humidity, and other external 

 agents, in modifying the characters of organs, which escape obser- 

 vation in the detailed study of a few specimens from a few lo- 

 calities only. 



It remains to say something of the plan of these Prsecursores. 

 They are intended to comprise catalogues of all the plants known 

 to us in each Natural Order ; and these, or groups of these, will 

 be prefaced by some general remarks. Well-known species will, 

 in most cases, be simply named, and only such synonyms and 

 references added as appear worthy of notice, and are not to be 

 found in DeCandoUe's ' Prodromus,' and other works of standard 

 authority in general use. We shall in many cases add as doubtful 

 synonyms, names of plants w^hich we have reason to think may be 

 such, or which at any rate deserve a closer comparison than we 

 can give. These references are, therefore, on no account to be 



* At least in the opinion of those who regard the essence of specific botany 

 to be the successful searching after difierences, however minute, rather than esti- 

 mating the value and significance of such differences, and tracing identity of 

 plan and structure under diversities of aspect, form, and external conditions. 



b2 



