POLTPODIUM VULGARE 



tacular clarity that the only difficulty in demonstrating the number with complete 

 finality is that the area occupied by the flattened nucleus is so large that an unusually 

 low magnification has had to be used in order to reduce the dimensions to that of the 

 printed page. 



At the time of publication of the preliminary note it was not certain whether some of 

 these types might perhaps have been of horticultural origin. This matter is, however, 



Fig. 127. Meiosis in hexaploid Po/v/'Ofl'n/OT from Windermere, fresh acetocarmine. x 1000. This was the 

 first specimen obtained and was illustrated in the preliminary note (Manton, 1947) at a lower 

 magnification. The chromosome number was at first thought to be 'c. 112', but is now known to 

 be III. Compare with Figs. 128-129. 



no longer in doubt. All three are characteristic and well-estabhshed components of the 

 European flora over very large areas, and in the normal condition show none of the 

 peculiarities which constitute the horticultural monstrosities to which varietal names 

 have so often been given. Each has, however, a distinctive morphological character, 

 and their separation in the field is a matter presenting no difficulty except where genuine 

 admixture due to hybridization is occurring. There is, moreover, strong reason to 

 suppose that not only are they distinguishable by their chromosomes and morphology 

 but that they also have characteristically different ecological, or perhaps more correctly 

 climatic, requirements which are reflected in differences of geographical distribution. 

 Owing to obvious difficulties in sampling populations in central and eastern Europe 

 at the present time, it has not yet been possible to investigate distributions fully. The 

 compilation of a map will therefore be deferred, but such information as is available will 

 be included in the description of each species in turn. 



MFC 129 9 



