SUMMARY. 
1. By investigations on the quantitative distribution of the life- 
forms in the floras, from temperate to progressively arctic regions, 
Raunkiær has shown that the chamæphyte percentage is subject 
to a steady increase from southern towards northern regions. Current 
conditions in the surrounding seas show an appreciable influence on 
the course of the individual Ch biochores, a warm northgoing cur- 
rent causing a decrease of the Ch percentage, while a cold south- 
going current causes an increase of the Ch percentage. This appears 
plainly from conditions along the coasts of Greenland and Iceland. 
2. If the Icelandic flora is divided into groups according to the 
northern and southern limits of the species, 7 species groups will 
result, distributed in 2 main groups. The 2 main groups represent 
species with respectively a northern and a southern distribution. The 
sub-groups within each main group differ from each other with re- 
spect to their northern limit. If the biological spectra of the in- 
dividual groups are examined, a continued increase of the Ch per- 
centage from the species group with the most southerly distribution 
to that with the most northerly distribution will be observed. If like- 
wise the variation of the biological spectra and the species group 
spectra in the flora lists of the separate parts of the country and 
altitudinal zones is examined, the variation is the same in both 
cases, but greatest in the case of the species groups. Species groups 
and life-forms may thus be regarded as indicators of environment 
and may be made the basis of considerations on external factors 
where these are unknown. 
3. Iceland’s Ch percentage ranges it among the boreal hemi- 
cryptophyte-chamaephyte climates, the Ch percentage for the whole 
country being 15.2. The 20 p. c. Ch biochore for the country as a 
whole lies at a level of c. 300 m above the sea. Between this line 
and the snow-line, which lies at a level of c. 1200 m, it is possible 
