X PREFACE. 



flowers, so as to get a clear conception of the terras by which 

 the several parts are known, as well as those by which their 

 characteristic features, taken either separately or collectively, 

 are indicated. It may be well further to point out, that it 

 would be by no means labour lost to commit to memory the 

 more important of the technical terms found in the Glossary. 

 The advantage of knowing their meaning would at once be 

 discovered on making real use of the book, 



Chelsea, 

 May, 1862. 



