Vlll PREFACE. 



SO called, liardly forms half of the first Book of the 

 Organography ; it is that part of the science in which 

 the most doubts and ambiguities are met with, the appli- 

 cation of which is the least frequent, and where the most 

 celebrated observers are almost all at variance upon the 

 most simple points of the observation of facts. Endea- 

 vouring to present this part of the science with as much 

 correctness as possible, I have then, after the example of 

 zootomists, given more importance to the study of com- 

 plicated organs, the function of which is the most evident, 

 the observation the most positive, and the knowledge the 

 most important in the whole science. 



In order to render the assertions of facts, of which this 

 work is almost entirely composed, understood, I have 

 been careful to quote numerous examples ; and as one 

 same example may frequently serve to elucidate the his- 

 tory of two classes of organs, I have not scrupled to 

 mention it twice when I think it necessary. I beg my 

 readers, beforehand, to excuse this kind of voluntary 

 repetitions, which have most frequently been caused by 

 the desire to quote for each case, examples the most 

 convincing, or the most easily verified. 



The alphabetical index to the names of the plants 

 mentioned in the work, which will be found at the end 

 of the second volume, will afford an easy means of 

 referring to the observations which may be there con- 

 tained ; but I must beg those who thus go to search 

 here and there for isolated facts, not to be surprised if 

 they sometimes find them either devoid of proof, or dif- 

 ficult to understand ; and I cannot tell how to conclude 

 these lines without referring to the request which I have 

 already made to my readers — not to judge of me by 

 isolated facts, but upon my opinions taken collectively. 



A. P. De C. 



