5o8 



THE POPULAR SCIENCE MONTHLY. 



ment was so simple that it is not worth while to give the diagram. 

 The leaflet fell slowly from the early morning till about 1 p. m. It 

 then rose gradually at first, but rapidly late in the evening. It occa- 

 sionally stood still for some twenty minutes during the day, and some- 

 times zigzagged a little. 



Fig. 11, Coronilla rosea: Leaf aeleep. 



The leaves of Coronilla rosea bear nine or ten pairs of opposite 

 leaflets, which during the day stand horizontally, with their midribs 

 at right angles with the petiole. At night they rise up, so that the 

 opposite leaflets come nearly into contact, and those on the younger 



A. B. 



Fig. 12. Desmodium gtrans : A, etem during the day ; B, etem with leaves asleep. Copied from 



a photograph ; fibres reduced. 



leaves into close contact. At the same time they bend back toward 

 the base of the petiole until their midribs form with it angles of from 

 40 to 50 in a vertical plane (as in Fig. 11), 



The appearance presented by a sleeping branch of Desmodium 

 gyrans and by one in the daytime, copied from two photographs, is 



