PLANTS. 209 



the first named we find a like connection and symmetry 

 as in the higher class of animals ; one plant is an inde- 

 pendent individual, as, for instance, the grasses, palm 

 tree, or onion-like bulbs. In these families, propagation 

 by buds or shoots is not to be thought of; their repro- 

 duction is effected by seed, tubers, or offsets from the 

 roots. It is, however, different in the compound species, 

 where many individuals are found on one stem. The 

 leaf buds and twigs of the apple may be considered each 

 as a separate member, and, if surrounded by moist earth 

 or moss at a particular point, will put forth roots without 

 a stagnation of the nutritive juices being necessary. 

 When these roots appear the branch may be cut, and so 

 separated from the parent plant, becomes a new individ- 

 ual. If a healthy branch or bud is carefully cut and 

 placed in an incision made between the bark and wood 

 of a tree belonging to the same species, it grows as read- 

 ily as on the parent plant, and is called grafting or 

 budding. These two examples serve to show that plants, 

 capable of propagation, are not simple or individual sub- 

 jects of the vegetable world, but one tree is a sort of 

 community of members, of which, like the coralline polyps, 

 many subsist on one stem. In the economy of simple 

 plants a different arrangement is observed between their 

 nutritive organs and those of the compound. The palm, 

 bulbs, and grasses come forth from the earth almost with 

 nearly the same thickness they ever attain. They in- 

 crease only in height, scarcely any in circumference. 

 The interior of the stems of these plants, when not alto- 

 gether hollow, is filled with a round cellular tissue, the 

 fine vessels of Avhich ramify in all directions. In these 

 classes, the stems, if closely observed, present no dis- 

 tinction between wood and bark ; in the compound 



