MOTtOK or THE FLOWER OF THE BARBEERY. %\S 



IX. 



On the Motion of the Flower of the Barhirry. In a Letter -* t 



from Mrs, Agues iBBETSOH, . *' 



To Mr. NICHOLSON. 

 SIR, 



.S the berberis has been the subject of a letter from one Motion of the 

 of your correspondents, 1 have waited till the flower was in flower of the 

 full beauty, to send you a sketch of the manner in which 

 the whole motion is managed by the spiral wire, I>r. Smith 

 has most properly observed, that it is a contraction of the 

 stem (for it can hardly be called a tilaraent) of the stamen : 

 it is so; for the contraction is in the spiral wire within this 

 stamen stalk, which is gathered up, as may be plainly seen, 

 when put into the solar microscope. Pi, VI, lig. 3, b 6ns 

 the corolla, a a the stamen fastened to it—it has also a 

 fastening to the pistil, which, crossing from each side to the 

 pistil and round it to the other stamen, makes a general 

 communication, but not a very sensible one. The strong 

 spiral wire, o o, that manages the flower, runs through the 

 middle of the stamen e c, with two joining from the sides 

 d d, and running into the nectaries, ff, in which they are 

 fastened at g g*» So uncommonly strong is this spiral wire, 

 that it is larger than that which manages many flowers of 

 three times the size. There are many cross spirals, for it is ' 

 rather a complicated management; but this will at least 

 account for the contraction that takes place from a to a, 

 and is plainly to be seen. The same thing happens in the 

 stalk of many plants when in bud, which alter their posi- 

 tion when full blown. On placing a bunch of these flowers Yh9 flowets ^ 

 under water, it is very difticult to make the water ^et to ^'i' ' tnove 

 them ; but if they are once thoroughly wet, they move uo lihe'tuhl^^*'^ 

 more. However I again repeat what I have said in my last roughly wel, 

 letter, that I cannot say I am myself convinced what is the 



• PI. VI, fig. 2, a a, shows the stem of ihe stamen of the l^rberry ii 

 its perfect state ; and fig. Q, a a, th« stem cat open t» expose the cases 



of the spiral wire. .1 * 



powery 



