324 



HETEROMORPHY. 



the two preceding, it-was seen that the spire included 

 the constituents of seven ordinary verticils. 



Here also may be mentioned a curious bamboo, the 

 stem of which is preserved in the British Museum, 

 and in which the internodes, on the exterior, and the 

 corresponding diaphragms and cavities within are spiral 

 or oblique in direction. 



The root is also subject to the same malformation, 

 the inducing cause being usually some obstiniction to 

 downward growth, as when a plant has been grown 

 in a small pot, and becomes, as gardeners say, pot- 

 bound. 



Fio. 174. Showing "pot-bound" root twisted spirally (from the 

 ' Gard. Chron.,' 1849). 



The axial portion of the flower, the thalamus, is also 

 occasionally twisted in a spiral direction, the lateral 

 parts of the flower being in consequence displaced. 



