XX1V INTRODUCTION. 
ulustrations from the immense number of recorded 
facts, the principle followed has been to choose those 
which seemed either intrinsically the most important, 
or those which are recorded with the most care. In 
addition to these public sources of information, the 
author has availed himself of every opportunity that 
has offered itself of examining cases of unusual 
conformation in plants. For many such opportunities 
the author has to thank his friends and correspondents. 
Nor has he less reason to be grateful for the suggestions 
that they have made, and the information they have 
supplied. In particular the writer is desirous of ac- 
knowledging his obligations to the Society, under whose 
auspices this work is published, and to Mr. 8. J. 
Salter, to whom the book in some degree owes its 
origin. 
The drawings, where not otherwise stated, have 
been executed either from the author’s own rough 
sketches, or from the actual specimens, by Mr. E. M. 
Wiliams. A large number of woodcuts have also 
been kindly placed at the disposal of the author by the 
proprietors of the ‘ Gardeners’ Chronicle.’? 
As it 1s impossible to frame any but a purely arbi- 
‘ In some instances diagrams and formule are given in explanation 
of the conformation of monstrous flowers; in general these require no 
further explanation than is given in the text, unless it be to state that 
the horizontal line — is intended to indicate the cohesion of the parts 
over which it is placed, while the vertical line | signifies the adhesion 
of the organs by whose side it is placed. The formula 

st st ST sT st 
shows that the sepals (s) are distinct, the petals (P) coherent, and the 
stamens (st) adherent to the petals. 
