220 GENERAL CHARACTER OP PLANTS. 



minates in a few months, and from the seed alone, is 

 then to be obtained a new generation of the species. 

 But in our perennial plants, trees, and shrubs, which 

 often die to the ground, or cast off their leaves at the 

 approach of winter, though the motion of the sap is ar- 

 rested by the influence of the cold, and the generation 

 of the year perishes ; yet, besides the seed, nature 

 has here provided an ample source of regeneration in 

 the innumerable buds, formed and ingrafted in the al- 

 burnum or sap-wood of the root or stem ; by this 

 means, at an early season of the year, an invariable 

 supply of vegetable beings are as plentifully produced 

 as required by nature. The buds of each tree or 

 plant, containing within themselves, individually, all 

 the rudiments of so many distinct vegetables, may be 

 transferred by ingraftment or growth in the earth, and 

 thus form as many distinct individuals, each again 

 subject ad infinitum to produce an additional ingrafted 

 progeny of buds and branches. The numerous 

 buds of each tree, nourished through the common 

 medium of the trunk and branches, perish after 

 developement and maturity, and are succeeded anew 

 by another generation of ingrafting or protruding 

 buds, for which they have provided by the deposition 

 of the alburnum. The growth of every tree, as well 

 as herb, is then strictly annual, and the trunk is pro- 

 duced by a curious junction of dead and living matter. 

 The rings of wood, which may be counted in the 

 transverse section of a tree, not merely indicates its 

 age, but the number of distinct generations of sponta- 

 neously ingrafted individuals which it has sustained. 

 In the animal kingdom, among the order Moluscae, 

 examples of this kind of aggregation are not uncom- 

 mon, where many animals are inseparately connected, 

 and nourished through a common medium. This 

 agamous race of plants are always similar to the pa- 



