IV 



PREFACE. 



close relationship existing between the Scrop/iulariacea, Atropacece and 

 SolanacetB, and the lines of demarcation subsisting between them ; I have 

 also endeavoured to trace the hmits of the several genera in the two last- 



mentioned families, and to show, at the 



time, their differential 



characters, adding my own opinions concerning their proper systematic 

 distribution. These arrangements are given in the Appendix to the First 

 Volume, together with the considerations upon which the several divisions 

 are founded, and the general Index has, in some measure, been made to serve 

 as a ready key to those references. The reasons that induced me to present 

 the examinations of the several genera in the unmethodical disposition in 

 which they appear in the body of the work, are also explained. In order 

 to elucidate and support my conclusions, I have given floral analyses in 

 all cases where I could obtain them, and plates are sometimes given of 

 well-known genera, to show the data upon which I hold to be distinct, many 

 groups that appear to me to have been associated together upon insufficient 

 grounds, in the elaborate Monograph of the Solan 

 admirable ' Prodromus ' : it will be seen in this last-mentioned work that 

 in many cases my views have been followed, while in others they have 

 been quite unnoticed or not adopted : in the end of the Appendix to this 

 Second Volume, I have discussed the grounds of these diffei 

 have adduced fresh reasons for the support of my & 



DeCandoll 



and 



It 



my 



the first 



3 have confined myself 

 whoHy to the consideration of South American plants, but in order to ex- 

 plain the affinities and differential characters of many of these genera, I 

 found it indispensable to institute a comparison between them, and others 

 of the Old World ; with a view, therefore, to preserve some degree of 

 consistency, the examination of the latter genera has been placed in the 

 Appendix to the Second Volume. 



Hamxnersmith, 

 Nov. 1857. 



