94 ORGANIC STRUCTURE. 



different forms and characters, as to bulk, structure, 

 position, place, and duration. 



There is, perhaps, no such thing- as a stemless 

 plant in nature, notwithstanding the term acdulis is 

 often used in botanical descriptions. There is always 

 some member between the root and fructification, 

 whether that be a tuber, bulb, scape, peduncle, or 

 ligneous column. The term is, therefore, to be under- 

 stood as only signifying that the plant is destitute of 

 an elevated flower stem, as Enothcra acaulis. 



The stem or trunk differs in size, from a diameter 

 of many feet to that of a bristle. In structure they 

 are solid or hollow jointed or simple single or 

 numerous. In position they are erect inclining, 

 prostrate, pendent or involving. In place they rise 

 in the air, creep on the surface, or enter deep into 

 the ground. In duration, if succulent they quickly 

 become decomposed ; if ligneous, they continue many 

 years before they fall to decay. The following are 

 examples of these different characters. 



The Quercus robur, some of the Conifer &, and 

 the Fagus Castanta attain the greatest magnitude 

 in temperate climes, and the BomoctXy Adansonia, 

 Tectoria, and perhaps the Swiet^nia*, are the most 

 stately genera in the tropical groves. 



The oak is also an example of a solid trunk before 

 its decay, and the best examples of hollow stems are 



* The writer is uncertain whether the mahogany he, or he not 

 a lofty growing tree ; hut from the soundness and great size of 

 the butts imported from Honduras and other places, it is quite evi- 

 dent that the tree lives to a great age hefore it decays at the heart. 



