Hollowat. — The Prothallus and Young Plant of Tmesipteris. 19 



Figs. 35-49. — Series showing development of the archegonia. Figs. 35-41 x 150; 



fig. 42 X 137; figs. 43-49 X 150. 

 Figs. 50a, 50b. — Series of transverse sections through mature archegonium from 



above downwards. X 137. 



