626 



On the Compass Plant. 



offer. The first communication was dated August 9, 1842, when 

 I delivered in person to the Secretary of the Institute, Francis 

 Markoe, Jr., a dried specimen of the plant. My second letter, 

 published, like the first, in the Proceedings of the Institute, was 

 dated January 25, 1843. 



My principal object now is to record the various experiments 

 which have, from time to time and in different places, been made 

 by me or under my direction, to demonstrate that the meridional 

 position of the plane of the leaf is due to the action of light. 



The property is best exhibited in the radical leaf, which pre- 

 sents its faces to the rising and setting sun. The flowering pl» nt 

 also exhibits the property, though imperfectly, but its leaves take 

 a medium position between their normal and symmetrical arrange- 

 ment in reference to the stalk, and the tendency to point towar 

 the north. But I have been not a little surprised to find the 

 figures of the plant, as given by A. W. B. (Professor A. W. Ben- 

 net) in Nature, Feb. 1, 1877, and by Sir Joseph D. Hooker in the 

 London Botanical Magazine for January, iSSi, present not the 



