— 208 — 



I have examined 2000 individuals from 20 different growing- 

 places (100 individuals from each place). In the tables I and II 

 (pp. 210—211) the result is stated. Only 10 of those 20 places are 

 inserted in the table as types. In order to give a clearer concep- 

 tion, table I only deals with the four first mentioned characters. 

 In table II five characters are considered. 



Each of the 24 possible combinations or Isoreagents has a 

 rubric in the table. They are arranged in such a way, that the 

 most typical arvensis-combmåtion parv, nib, nmc, ap stands at 

 the top, and the most typical ^rico/or-combination gr, lab, mac, cl 

 at the bottom of the table. In the middle the middle forms are 

 to be found. 



The growing-places examined are indicated by capital letters 

 as follows: 



A: Grass field at Herlev, Sjælland, u / 6 18. 

 B: Waste-place at Gentofte, Sjælland, 31 / 5 18. 

 C: Grass field, Tysinge Moor at Tølløse, Sjælland, 8 / 6 18. 

 D: Grass field, Egby at Glostrup, Sjælland, 2 / 6 18. 

 E: Sandy rye field near Ordrup Næs, Odsherred, Sjælland, 

 »/, 19. 



F: Sandy grass field, stone quarry at Frederikshavn, Jylland, 

 24 / 7 19. 



G: Grass field, Sophienholm Hills at Tølløse, Sjælland, 29 /s 19. 

 H: Plantation of spruce-fir, Sophienholm Hills, 8 / 6 18. 

 I: Dunes on Læsø, (island in Kattegat), 22 / 7 19. 

 K: Dunes near Skagen, Jylland, 4 / 8 19. 



In the columns the examined individuals are distributed be- 

 tween the different Isoreagents. As the number of individuals 

 from each place is 100, the figures to some extent indicate the 

 °/ 0 of frequency of the Isoreagent in question. 



The distribution of all the 1000 individuals can be seen from 

 the last section in table I. As will be seen, 20 of 24 possible com- 

 binations are represented. This distribution, with fairly free com- 

 bination of the characters, might suggest, that in the main crossing 

 is the cause of the great diversity. Also from the point of view 

 of modern Mendelism it is the most likely explanation. 



The different growing-places have populations very differently 

 constituted. The character of A and B is a pure arvensis. 96 °/ 0 

 are composed parv, nib, nmc, ap and the remaining 4 °/ 0 falls upon 

 the next isoreagent. — On the other hand C, D, E, F and G are 



