LECT. IX.] HYBKRNACULA GEMS. 469 



the gem opens in spring; and it is invariably 

 the same in individual plants of the same spe- 

 cies. The process is termed FOLIATION *, and the 

 figures which the leaves assume at the time, 

 have received different appellations. In noticing 

 these I shall arrange them under the three fol- 

 lowing heads : Folded, jo Overlapping, and y 

 Rolled; and mention the varieties of each kind. 

 The best method of ascertaining the character of 

 a gem, as respects its foliation, is to cut it across 

 while it is opening, and to examine the sections 

 of the leaves. 



oc. Folded. This kind of foliation displays the 

 leaf- or its parts variously doubled together. 

 There are two varieties of it : the doubled and the 

 plaited. 



1. In the doubled (condu- 

 plicata), the two sides of the 

 leaf lie parallel to each other, 

 as exemplified in the Oak, the 

 Walnut, the Cherry, the Beech, 

 the Rose, &c. In the marginal 

 cut, a. shows the section of a 

 leaf, and b. the entire opening 

 gem of the Lime tree, Tilia 

 Europea, which is an excellent 

 illustration of this variety. 



* FOLIATIO est complicatio ea, quam servant folia, dum 

 intra Gemmam aut Asparagos plantarum latent. Phil. Bot. 

 163, iv. 



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