PREFACE. vu 
drawings were made from fr eshly-gathered specimens, so that the 
peculiarities of the lines which give so much character to different 
styles of growth might be if possible rendered. All the dissections 
are represented as being magnified to a greater or less degree, except 
in a very few instances when special mention is made to the contrary 
in the accompanying letter-press. 
I can only hope that the Reader may find that an ever-increasing, 
ever-widening interest attends his researches, till many other branches 
of science link themselves into his original study, and make the 
pursuit endless though never in vain. 
September, 1864. 
