C. Cool and A. N. Koopmans 
45 
accords with the one that we can expect when we know only the other points and 
causes the variation polygon to become rather symmetrical with regard to the 
vertical through the mode. 
Frequency of 
the terminal umbels 
wumaRArs 
Fig. 4. Anlhriscus sylvesiris. 
Variation of the number of umbel rays of the lateral umbels of the first order and 
correlation of the number of umbel rays of terminal umbels and that of lateral umbels. 
Of 235 plants (being the same series for which the rays of the terminal umbels 
were counted and which were included in the preceding distributions) the number 
of umbel rays of the lateral umbels was determined. 
Again these lateral umbels were divided into groups, in the first place into 
groups belonging to plants with the same number of rays in the terminal umbel, 
and in the second place into groups belonging to plants with the same number of 
lateral umbels. 
In the following table have been assembled the results of the countings on 
1632 lateral umbels of these 235 plants in which the first sub-division was taken. 
It is easy to see that the numbers 8 and 10 are predominant. 
