PREFACE. 
freest access to his extensive herbarium, which is_parti- 
cularly rich in the botanical productions of South America. 
From this fertile source, and the different herbaria in the 
British Museum, as well from the materials in his own 
collection, he has prepared the following contributions, 
accompanied by illustrations and the details, which ac- 
cording to his views, tend to exemplify the characters of 
each genus referred to, The vast accumulation of plants 
during the last few years, collected in all parts of the globe, 
has been so great, that it becomes absolutely necessary to 
define with greater accuracy the limits, not only of genera, 
but of species, and where this can be accomplished upon 
sufficient evidence, much will be done towards removing 
the confusion that exists in many cases; but even should 
the author of these Illustrations succeed in only a few in- 
stances, he hopes to render some service, though it be not 
very great, towards the advancement of the science of 
Botany. ! 
A portion of the text that has first appeared, and will be 
continued at different intervals in the “ London Journal of 
Botany” under the title of “ Contributions to the Botany 
of South America,” is here reprinted with a few alterations, 
and a description in detail of the several plates offered as 
“ Illustrations” of these respective subjects, will be given 
at the end of each part; these will be drawn on stone by 
the Author, who claims much indulgence for the many 
imperfections attending his first attempt at any work of the 
kind; 22;[ 4 on 
Hammersmith, 
July, 1846, 
