MAHTIUS ON THE BOTANY OF BRAZfl,. 29 



ness and afBnity of species in one and the same genus. These 

 close boundaries of the specific forms, and the variableness 

 of the individuals, are substantial difficulties in the study of 

 a Flora so rich in species as that of Brazil. The Melastoma- 

 cece and Myrtacecs of the Brazils, that are in De Candolle's 

 Prodromiis, may serve as an evidence of the correctness of 

 this assertion. It is, therefore, not surprising, if many species 

 are already introduced into systematic works, whose right to 

 that rank will be doubtful, until they are more studied in 

 their original localities. With a view to these two circum- 

 stances, must be taken into consideration that which will 

 necessarily escape the traveller who passes hastily through the 

 country : I mean the formation of hybrids, and the difference 

 of the individual in the development of the flowers in the 

 two sexes. There can be no doubt that the numerous in- 

 sects in Brazil industriously visit the expanded blossoms, 

 and produce similar effects to what are known to occur by 

 a similar cause in Europe. So, too, will greater accuracy, 

 and much time, be required to prove that certain variations 

 in the growth, the inflorescence, even also in the leafing, are 

 or are not occasioned by the differences of sex in the nume- 

 rous polygamous and dioecious plants that occur in the Flora 

 of the Brazils, and which have not been accurately distin- 

 guished. Similar differences with those in the German species 

 of Tussilago, or in Serratula arvensis (ascertained by Mr 

 Brown to be dioecious) will be discovered in Brazil in many 

 species of Eupatorium, Mikania, Baccharis, 4'C- 



After these few introductory observations on the character 

 of the Brazilian vegetation in general, Von Martins proceeds 

 to offer some remarks on the peculiarities presented by the 

 different regions of the vegetation in Brazil. There, as in 

 every Flora of great extent, are spread over the wide surface 

 of the country, various masses or groups of vegetables in 

 such a manner, that each in its intensity, that is, where it 

 appears complete and unmingled, bears its own peculiar 

 character. This character is recognised no less physiogno- 

 mically, in the stamp of its whole picturesque appearance, 



