APOGAMOUS FERNS. EVOLUTION OF THE SEPARATE SPECIES 

 geographical details of members of the series, although some preliminary facts are 

 available from the fom- countries mentioned above. In an unpubhshed communica- 

 tion from Mrs G. Knaben of Oslo, which I am permitted to quote, the first chromosome 



Fig. 198. Comparable pinnae of the polyploid series in Dryo^tem ^orrm Newm. Natural size. 



a, diploid; b, triploid; c, tetraploid; d, pentaploid. 



count for Norway is 'approximately 125'. In Germany we have Dopp's record of 

 approximately 130, and in Britain and Switzerland there are my own records of 

 '«' = 123. There seems httle doubt therefore that the triploid is the commonest form 



189 



