LEAF-ARCHITECTURE AS ILLUMINATED BY A STUDY OF PTERIDOPHYTA. 673 



Prantl applied a similar analysis to the leaves of Aneimia and Mohria, and 

 found that they were susceptible of a similar interpretation ; but in them the apical 



growth is limited. 



a 



Fig. 7.— Schematic drawings after Pbantl, showing the sympodial development 

 in leaves of Lygodium circinaticm. (See text. ) 



As material was available from my Jamaican collections, it was thought worth 

 while to examine and depict the successive stages of the juvenile leaves of Aneimia 

 adiantifolia (fig. 7 bis, 1-1 1). The simplest leaf is seen in (l) : it shows a single 



10 9 



Flo. 7 bis, 1-11. — Successive stages of development of the juvenile leaves of Aneimia adiantifolia. ( x 4.) 



forked vein, and two equal distal teeth. Transitional stages (2, 3) lead to a double 



dichotomy, with four equal distal teeth. The two limbs of the dichotomy begin, in 



more elaborate forms (4-7), to develop unequally, while a deeper indentation marks 



off the two lobes. Each of these is supplied by the branches of one limb of the 



fundamental dichotomy, and each has distal teeth corresponding to the veins. The 

 TRANS. ROY. SOC. EDIN., VOL. LI, PART III (NO. 21). 99 



