370 



MOSSES AND FERNS 



CHAP. 



the sporangial receptacle, were found to be a common pheno- 

 menon in the same species. 



The ScJiizceacecE^ 



The Schiz^eaceae include about sixty species belonging to 

 five genera. The very characteristic sporangia have a terminal 

 annulus, which forms a sort of crown at the apex. Some of 

 them, like Schizcza pusilla and Trochopteris elegans, are very small 



Fig. ig2. —Lygodiinn Japonicmn (Sw.). A, Pinnule, x 3 ; j, the sporangial segments; B, horizon- 

 tal section of one of the latter showing the sporangia, sp, X 14 ; C, a single sporangium, showing 

 the terminal annulus (r), X 65 ; D, cross-section of the petiole, X 65. 



and delicate species ; the largest species of Lygodiu7ii have 

 fronds 2 or 3 metres in length, but always slender and delicate 

 in texture. 



The development of the prothallium corresponds closely to 

 that of the Polypodiace^,^ but there are one or two peculiarities. 

 The spores are always of the tetrahedral form, and without 

 chlorophyll. The germination follows as in the Polypodiaceae, 



Prantl (5). 



- Bauke, Pringsheims Jahrb. f. wiss. Botanik, vol. xi. 



