92 PREFACE. 
but a single flower. Such a result, derived from so much 
previous experience, cannot have existed in every case; and 
some perhaps of our new species, founded upon imperfect 
materials, or even those assimilated to species already 
known, may not carry with them equal authenticity. But 
so much care has been taken in ascertaining their identity, 
essential for botanico-geographical data, that it is hoped 
that no grave errors have occurred. Collected, too, ™ 
different seasons, deficiencies of one set were occasionally 
made up by the better state of those supplied by other tr& 
vellers. E 
The most complete collections were those of Dr. J. D. 
Hooker and the much lamented Theodore Vogel. They 
may be said to form the groundwork of the Spicilegi@i 
though both were formed in the dry season, that of Dr 
Hooker in November 1839, and that of Vogel in June 
1841. Another very interesting set, gathered by Forbes 
in a much better season, March and April 1822, and 
most liberally communicated by the Horticultural Society; 
has afforded many species in the best order. To these must 
be added a small collection made by that accomplish 
naturalist, Mr. Darwin, (the property of the Cambridg? 
University Museum) and generously confided for pub- 
lication to Dr. Hooker by Professor Henslow: it has 
added some interesting species to the catalogue. The 
rules of the British Museum forbid the loan of the treasures 
contained within its walls; and it is through the collation 
by Dr. J.:D. Hooker of the specimens of the other herbaria 
with that of Christian Smith, preserved in that establish- 
ment, that I have been enabled to cite his plants and t0 
quote the catalogue, contained in his journal, published 1? 
Captain Tuckey’s Voyage to the Congo. Those of Forster 
I have not been able to see. à 
The late Dr. Brunner, of Berne, on his return from Senegal, 
visited several of the Cape de Verd Islands. The species he 
there gathered appeared in his Ergebniss, originally published 
in the “ Flora od. Bot. Zeitung.” 1 was obligingly furnished 
