Lesson xxx!v.] VEGETATION. 



titiule of annual Plants, than a perennial indi- 

 vidual. The sap in trees always rises as soon as 

 the frost is abated, that when the stimulus of the 

 warm weather in the spring acts upon the bud, 

 there should be at hand a supply of food for its 

 nourishment; and if, by any means, the sap is 

 prevented from ascending in proper time, the tree 

 inevitably perishes, as has been very frequently 

 observed. 



Before I conclude this Lesson, I cannot forbear 

 paying a few words on the different manners in 

 which Plants disseminate their seed. Having gone 

 through the progressive stages of springing, flower- 

 ing, and seeding, fhey liave at length brought to 

 maturity the rudiments of a future progeny, which 

 are>now to be deposited in thefostering bosom of the 

 earth. Seeds are scattered by the hand of nature 

 in various ways. Those of them which are furnish- 

 ed with plumes, or wings, are dispersed about by 

 the high winds which blow soon after the Autumnal 

 Equinox, the time of dissemination. Hence Plants 

 with such seeds are, of ail others, the most generally 

 to be met wkh: as dandelion, groundsel, thistles, 

 &c. Others by means of hooks, with which 

 they are furnished, lay hold of passing animals, 

 and are thus carried to distant places : the common 

 burs are examples of this contrivance, Several 

 when ripe are thrown out with considerable force, 

 from their receptacle, by means of a strong spiral 

 elastic spring; of this the impatiens,or touch-me- 

 not, and all the species of cardamine, or cuckoo- 

 flower, are instances. Many are co; tamed in 



berries, 



