DISPIiACEMENT OF LEAVKS. 87 



axis. There were several bracts beneath this flower 

 disposed spirally in the ^ arrangement, ail being empty, 

 excepting the terminal one. In like manner, a head 

 of flowers becomes sometimes converted into an umbel. 



Displacement of leaves. A cohesion of parts will some- 

 times give rise to an apparent displacement, but the 

 true nature of the malformation can, in general, be 

 readily made out. 



SteinheiP found a specimen of Salvia Verbenaca, the 

 leaves of which presented very curious examples of 

 displacement arising from cohesion. Two of these 

 leaves placed at the base of a branch were completely 

 fused in their lower thirds, and di\4ded into two dis- 

 tinct lobes at the upper part; each of these lobes 

 seemed to be as large as the limb of an ordinary leaf. 

 Above these was another very broad one, apparently 

 entire, but evidently produced by a complete cohesion 

 of two. This completely fused leaf alternated in 

 position with the imperfectly fused one below it ; the 

 alternation is explained by supposing that the opposite 

 leaves of each pair were directed one towards the 

 other, and became fused, and that thus resulted the 

 displacement. The dislocation of the organs took 

 place in one dii'ection for one pair of leaves, and in 

 another direction for the other pair, hence the alter- 

 nation. Thus, leaves normally opposite and decussate 

 may, by fusion, become alternate. A similar instance 

 occurred to the writer in Lijshnachiu vulgaris^ wherein 

 the changes arising from fusion and suppression of 

 parts, &c., were very considerable ; as far as the 

 leaves were concerned they presented the following 

 arrangement in succession from below upwards : first 

 verticillate, then opposite, then spirally alternate, lastly 

 opposite.' The term '* diremption" has sometimes 

 been applied to cases where leaves are thus appai'ontly 

 dragged out of position. 



' Ann. Sc 

 See Kii*8c 



Nat.,' ser. 2, vol. iv. 1835. p. 143, tab. v. 

 lilegcr. Flora,' IS-W. p. 50b (Scabiosa). 



