3Q4 PROPAGATION OF THE SPECIES. CHAP. IX. 



have no doubt of the existence of an umbilicus in 

 the chorion of the Laurel. 



CHAPTER IX. 



THE PROPAGATION OF THE SPECIES. 





As the life of the vegetable, like that of the animal, 

 is limited to a definite period, and as a continued 

 supply of vegetables is always wanted for the sup- 

 port both of man and beast, nature has taken care 

 to institute such means as shall secure the multiply- 

 ing and perpetuating of the species in all possible 

 cases ; art has invented others for the use and ac- 

 commodation of man, and fancy has imagined more. 



SECTION I. 



Equivocal Generation. 



IT was long a vulgar error, countenanced even by 

 the philosophy of the times, that vegetables do often 

 spring up from the accidental mixture of putrid 

 water and earth, or other putrid substances, in the 

 manner of what was called the equivocal generation 

 of animals ; or at the very least, that the earth con- 

 tains the principle of vegetable life in itself, which 

 in order to develope it is only necessary to expose 

 to the action of the air. The former alternative of 



