VI PREFACE. 



as they were delivered to my pupils, exposed for 

 sale in a bookseller's shop*. Reflecting, therefore, 

 that any peculiar theories connected with vege- 

 table physiology, which I had taught, and of 

 which little more than outlines had been sketched 

 for the class-room, were likely to be much mis- 

 represented, and even that many of the facts 

 taken from authors might be misstated, justice to 

 my reputation required that I should rather pub- 

 lish my own opinions, than run the hazard of 

 their getting into the press in a mutilated condi- 

 tion. In revising my manuscript, however, for 

 this purpose, I found that the view of the sub- 

 ject opened before me, that one investigation led 

 on to another; and that a frequent appeal to Na- 

 ture forced me to reject much of what I had for- 

 merly regarded as truth ; so that the work im- 

 perceptibly extended far beyond the limits I had 

 allotted to it; and, now, retains little more than 

 the name and the arrangement of the original 

 Lectures. 



The present volume treats of the forms and 

 the anatomy of those organs which are necessary 

 for the growth and the preservation of the vege- 



