LECT. VI.] THE STEM. ITS DIRECTION. 243 



thread which supports the flower of the bending 

 Hairbell, and the rigid trunk of the majestic 

 Oak ! and in position and altitude, betwixt the 

 creeping Bramble and the towering Palm, rising 

 to the height of upwards of two hundred feet ! 

 Some of the climbing plants have been found, 

 when untwisted, to be five hundred feet in length : 

 and Captain Cook observed, that in parts of the 

 ocean, where the soundings were upwards of thirty 

 fathoms, the sea- weed stretched in a direct line 

 from the bottom to the surface of the waves. The 

 diversity in the thickness or diameter of the stem 

 is not less remarkable. In the Club-rush, Scirpus 

 capillaris, it is quite a hair, while Swilcar Oak, 

 on the contrary, is thirteen yards in circumference 

 round the base of the trunk, and eleven yards at 

 the height of four feet from the ground : in Ches- 

 nut trees it has been known to acquire, even in 

 Great Britain, forty feet in circumference; and 

 we are informed that the trunk of the Calabash 

 tree, Adansonia digitata, which grows on the coast 

 of Africa, although not more than twelve or four- 

 teen feet in height before it branches, is frequently 

 twenty-seven feet in diameter*. Such is the 

 amazing extent to which the stem may attain ; 



* " The branches of the Adansonia, which are numerous 

 " and thick, extend from thirty to sixty feet out from it in 

 ** all directions; and the hollow trunk is often the dwelling of 

 " several negro families.'* Fam. des Plantes, Pref. ccxii. 



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