LECT. IX.] HYBERNACULA GEMS. 473 



5. The Turned down (Redinata), in which 

 the leaf hangs down and is wrapt 

 round the footstalk, as in the buds 

 of officinal Wolfsbane, Aconitum neo- 

 montanum ; the genus Anemone, &c. 

 In the marginal cut representing an 

 unexpanded leaf of Duck's-foot, Po- 

 dophyllum peltatum, a. a. shows the 

 leaf wrapped round the footstalk b. c. 



As the gems open, the leaves gradually unfold 

 themselves, and assume their natural forms ; but 

 the opening of the bud does not, in every in- 

 stance, immediately set free the leaves; for, in 

 some gems, each leaf is separately enclosed in a 

 membranous cover, which opens either laterally 

 or at the apex, and permits the leaf to expand. 

 This covering is generally regarded as a stipule 

 (stipula); but it scarcely accords with Linnseus's 

 definition of that appendage* ; and may rather be 

 considered as a protection to the embryon leaf, 

 until it has attained sufficient vigour to bear the 

 stimulus of light, and to admit of that degree of 

 perspiration, which its exposure to the atmo- 

 sphere occasions. The gem of the Tulip tree, Li- 

 riodendron Tulipifera, affords a very beautiful ex- 

 ample of this form of foliation. The leaf before 

 expanding is conduplicate and arched, or bent 



* " Stipula est squama, quae basi petiolorum aut pedimculo- 

 " rum enaseentium utrinque adstat." Phil. Bot. 84. 



