182 H. MØLHOLM HANSEN 
consideration, the frequency of the species gradually decreases, i. e. 
the distance between individuals grows greater and greater and at 
last the species entirely disappears. This applies to all species. The 
individual species may be distinguished with respect to the position 
of the maximum in the scale, the magnitude of the maximum, and 
the number of degrees in the scale which the species covers. 
The proportional distribution of the species in a given scale has 
proved the same wherever it has been more closely investigated. 
The distribution of Raunkiær’s life-forms in the scale of ex- 
ternal factors is the same as that of the individual species. The 
sequence of the maxima of the life-forms in the scale of moisture 
from the most moist to the driest section is as follows: HH— G—> 
H—Ch— (Th). This sequence occurs wherever conditions have been 
closely examined and remains the same whether the succession is 
determined by means of the number of individuals (frequency sum) 
or the number of species. 
In the scale of snow-covering, Ch occur in greatest quantity 
in the “sections devoid of snow”, H in the opposite sections. These 
conditions are repeated wherever the facts have been investigated, 
and remain the same whether calculated by means of the number 
of individuals or by means of the number of species. 
The distribution of the species groups in the scales of external 
factors would seem to open up new possibilities of determining the 
factors which are active in the distribution of plants. 
Fig. 1 is to be found on page 21, the others are printed on 
plates I—XII. 
