PL A.TE XI. 



Fig. 



1. Sisymbrium Alliaria (Garlic-Mustard). An ovular 



leaflet bearing an adventitious shoot. (After Cela- 

 kovsky). as, adventitious shoot; it, inner integu- 

 ment; ot, outer integument, p. 138. 



2. Polystichum aculeatum (Prickly Shield-fern). A spo- 



rophyte apogamously produced on a prothallus. 

 (After Lang.) p. 140. 



3. Athyrium Filix-foemina var. clarissima. Prothalli 



sprouting from the sorus of a leaf (apospory). anth, 

 antheridium ; arch, archegonium ; pr, prothallus ; 

 pi, pinnule. (After Bower.) p. 141. 



4. Scolopendrium vulgare (Hart's-tongue). A rudimen- 



tary adventitious shoot growing out of an archego- 

 nium. sp, sporangium. (After Lang.) p. 140. 



5. Nephrodium pseudo-mas var. cristata. Apogamous 



transition from prothallus to sporophyte, and subse- 

 quent aposporous transition to prothallus at apex 

 and margins of leaf. pr, prothallus ; sph, sporo- 

 phyte. (From Bower, after Lang.) p. 145. 



