V] 



EQUAL DICHOTOMY 



S7 



{Trichomanes, Ceratopteris). But usually the cotyledons show equal dicho- 

 tomy, while the later leaves show inequality of the forking, leading gradually 



Fig. 79. Basal part of the lamina of an adult sterile \t?S oi Elaphoglossum {Rhipidopteris) 

 peltatum, showing very perfect dichotomy. ( x 4.) 



Fig. 80. Successive juvenile leaves of Osmiinda regalis, showing successive steps of 

 progression from equal dichotomous venation to sympodial branching, and the 

 establishment of a terminal lobe. { x 2^.) 



to a dichopodium {Cyathea, Anemia, Osmunda, Fig. 80). Where, however, 

 the first leaf is relatively large it may at once step into a more advanced 

 position, and the initial state of equal dichotomy is apt to be omitted. This is 



