GENERAL RESULTS— SPHENOPSIDA 629 



had specially favourable opportunities for the investiga- 

 tion of Tmesipteris under natural conditions. He has 



Fig *%■$— Tmesipteris. A. Somewhat diagrammatic radial section of synangium and 

 part of sporophyll, showing vascular bundle, v.!:, passing into sporangiophore from 

 sporophyll ; on the right a fragment of one of the bundles of the forked sporophyll IS 



shown. . , , • t . .v. 



B Transverse section of synangium and sporophyll tn a plane lying between the 



sporangiophore and the stem. In the sporophyll three bundles are shown, the middle 



strand belonging to the sporangiophore and the two laterals to the forked sporophyll. 



found that certain interesting variations normally occur 

 in the species. The most important variation consists 

 in the repeated bifurcation of the sporophyll, a synangium 



