OT REVERSED PLANTS. 50 



just described, when cut across shows some- 

 thing of a circular arrangement of fibres, 

 arising from the original disposition of the 

 leaves. The common orange lily, Lilium hul* 

 biferum, Curt. Mag, t. 36, and white lily, 

 L.candidum, f.278, which belong to the same 

 natural family of monocotyledones, serve to 

 elucidate this subject. Their stems, though 

 of only annual duration, are formed nearly 

 gn the same principle as that of a Palm, and 

 are really congeries of leaves rising; one above 

 another, and united by their bases into an 

 apparent .stem. In these the spiral coats of 

 the sap-vessels are very easily discernible. 



To conclude this subject of the propulsion 

 of the sap, it is necessary to say a few words 

 on the power which the vessels of plants are 

 reported to possess of conveying their appro- 

 priate fluids equally well in either direction ; 

 or, in other words, that it is indifferent" whe- 

 ther a cutting of any kind be planted with its 

 upper or lower end in the ground. On this 

 subject also Mr. Knight has afforded us new 

 information, by observing that, in cuttings so 

 treated, the returning vessels retain so much 

 of their original nature as to deposit new wood 



