THE OTHER BRITISH FERNS— POLTSTICHUM, ATHYRIUM, CETERACH 



found by me on separate occasions in the summer of 1937 in the North Itahan Alps 

 and brought aHve to England, where they unfortunately perished during the war, but 

 not before successful fixations had been made. To replace them additional material 









O 







o 





<^«^%-^0 



d?0 





o 







O ^ Oof) 



(p 



/4. germanicum 3n = /^5 



Fig. 100. 



Fig- 99- 

 Fig. 99. The cytology of /ii-/)/fm«m ^ermaw/cM?n auct.non Weiss, x 1000. For explanatory diagrams see 

 Fig. 100. a. Meiosis in a section of an Italian specimen showing lagging univalents, b. Meiosis 

 in the Welsh specimen in balsam after acetocarmine showing pairs and univalents, c. Two focal 

 levels through a mitotic figure in a root of the Welsh plant showing the triploid chromosome 

 number. 



Fig. 100. Explanatory diagrams to Fig. 99^*, c. x 2000. 



was obtained in the summer of 1948 consisting of one plant from the island of Runmaro 

 near Stockholm, Sweden, kindly procured for me by Professor Halle and posted to the 

 Royal Botanic Gardens, Kew; and a Swiss plant found near Sion by my colleague. Miss 

 Davies, and brought back by her to Leeds. A leaf of the Swedish specimen is reproduced 

 in Fig. 97^. 



104 



