146 



MORPHOLOGY OF SPERMATOPHYTES 



strobili, 7 however, are the most interesting of Wieland's results 

 thus far. The staminate strobili originally described 4 were 

 taken from specimens of Cycadeoidea ingens, and apparently 

 resemble the ovulate strobili of the group in all important fea- 

 tures. Each strobilus is borne 

 terminally upon an axillary 

 dwarf shoot, and is ensheathed 

 by a cluster of bracts. There 

 is plain indication of the ex- 

 istence of a thick central axis 

 upon which the numerous 

 sporophylls were crowded, 

 each sporophyll bearing nu- 

 merous sori. This first mea- 

 ger description of a staminate 

 strobilus has been supple- 

 mented by lattr preparations 

 of Wieland from the strobili of 

 the remarkable Cycadeoidea 

 Dacotensis. 5 "With great gen- 

 erosity Dr. Wieland has placed 

 these recent preparations at 

 our disposal, and from them the 

 following account is written: 



The strobilus of Cycadeoi- 

 dea Dacotensis is of the usual 



ovoid form, being completely ensheathed by overlapping sterile 

 bracts. Just within the ensheathing bracts there is a set of very 

 prominent microsporophylls, whose abaxial surfaces are densely 

 covered by well-defined sori (Fig. 101). As is evident from the 

 figure, and much more conspicuously so in other preparations, 

 the sori occur closely packed together in well-defined lines. The 

 section of a sorus reveals characters unknown heretofore among 

 Gymnosperms, and remarkably similar to those of Marattiaceae 

 (Fig. 102). The structure seems to be almost identical with 

 that of the synangium of Marattia or of Danaea, and presents 

 more the appearance of a plurilocular sporangium than of a 

 sorus. Superficially there is a wall of heavy cells, and between 

 it and the regular sporangial chambers there is a more delicate 

 tissue. The sporangial chambers, separated from one another 



FIG. 101. Cycadeoidea Dacotensis, a small 

 part of a radial oblique section of a stro- 

 bilus, showing some of the numerous 

 synangia, x 8. From preparation made 

 by G. R. WIELAND from specimen in 

 Yale University Museum. 



