278 CONSERVATIVE ORGANS. [LECT. VI. 



innermost layer of each of the united stems into 

 contact ; for, were this the case, the pith of each of 

 these conjoined stems would be still entire, and 

 the aggregate would appear as distinct cylinders, 

 according to the number of the stems ; whereas 

 in the fasciculated stem there is one flat pith 

 only, and the other parts of the stem are, in ar- 

 rangement and number, the same as if the ano- 

 maly did not exist. The idea, therefore, of the 

 fasciculated stem arising from the pressure of one 

 or more contiguous stems, and a natural graft 

 being thus formed, as has been suggested by Mr. 

 Keith, cannot be admitted. Several other ano- 

 malies occur in the configuration of stems ; but 

 as these are generally either the consequence of 

 disease, or of some obstacle to the natural de- 

 velopment in the individual plant occasioned by 

 insects, the consideration of them may be de- 

 ferred until we come to treat of the diseases in- 

 cidental to the vegetable system. 



Independent of the diversities which we have 

 already examined, STEMS have been properly distri- 

 buted into distinct species. In this classification, 

 Linnaeus and others who have copied after him, 

 enumerate six species of stems ; but among these 

 the footstalk of the leaf and the frond are impro- 

 perly included ; for, as the former is decidedly a 

 part of the leaf, and separates with it when it falls ; 

 and the latter is a peculiarity connected with the 

 foliage of distinct tribes of plants, the Palms, the 



