FACTORS OF INCREASE 



125 



Ophioglossaceae and Filices, and in these the continued apical growth may 

 largely devolve upon the sporophylls. The consequence of such growth 

 is increased accommodation for sporangia. Similarly, continued intercalary 

 growth may effect the same end : as in the sori of those Ferns designated 



FIG. 67. 



A forked sporangiferous branch of Lycopodium chamtpcyparissus in longitudinal section, 

 ~liu r htly magnified. _ff= the axile vascular body. M = leaves. ss = young sporangia. 



the Gradatae. These serve as examples of the way in which, by continued 

 growth of the parts which bear the sporangia, a sequence of these may be 

 produced, which may be continued so long as the growth itself. It is clear 

 from the examples adduced that such continued growth may occur in parts 

 which are not morphologically comparable. In the more primitive Pterido- 

 phytes it is answerable for extensive increase in accommodation for primordia 

 of sporangia. 



