SLEEP OE J'L.LXTS. 



253 



remarkable. The leaf is 

 a very compound one (fig. 

 40) consisting of a petiole 

 with about seven pairs of 

 pinna;, or secondary peti- 

 oles, each of which is 

 feathered with little leaf- 

 lets. Towards night the 

 pinna; move forwards, 

 and sink downwards. 

 The leaflets become 

 directed towards the apex 

 of the pinna, and over- 

 lap each other, so that 

 the " pinna; then look 

 like bits of dangling 

 string" (fig. 41). Merc 

 verbal description can 



E/i^. 40. — Leaf of Aiacia Far- 

 iicsiana awake. 



Fig. 41. — Leaf of ^t(7(.7iz Eanicsiana in a sleeping condition, 

 give no idea of the contrast betv.een the appear- 



