THE HOMOSPOROUS LEPTOSPORANGIATJE 



371 



may divide (Fig. 211). At this stage there is a marked re- 

 semblance to the sporangium of Angioptcris, and Bower calls 

 attention to the similarity in form between the sorus of Gleich- 

 enia and that of the Marattiacese. The walls of the inner 

 tapetal cells are finally absorbed. The number of sporogenous 

 cells is large, the number of spores in G. Hahcllata amounting 

 sometimes to over 800. 



In G. dichotoina (Fig. 212) the sporangia form rounded 

 naked sori above the terminal branch of a lateral vein. They 

 are pear-shaped, with a very short stalk, and upon the outer 

 surface is a nearly complete very distinct annulus composed of 



Fig. 213. — Matonia pectinata. A, Base of fertile pinna, X3; B, section of the sorus; 

 C, open sporangium, X3S; D, section of rhizome, Xio. (A, B, after Diels; D, 

 after Seward.) 



a single row of large thick-walled cells. This is interrupted 

 at the top of the sporangium by three or four narrow thin- 

 walled cells, and starting from this point and extending along 

 the median line of the ventral surface are two rows of narrow 

 cells, between which the sporangium opens. 



The Matoniace^ 



• The family Matoniacese is represented by the single genus 

 Matonia (Fig. 213), with two species, M. pectinata and M. sar- 



