42 Floristik, Geographie, Systematik etc. 



CI. p. 361) is based upon the degree of protection attained by the buds 

 surviving the unfavourable season. The foundation of life-forms on 

 this base touches one of the most essential things in plantlife, and 

 besides is easy in use and homogenous, allowing a Statistical treat- 

 ment of the vegetations. 



In Order to facilitate the foUowing, the essential types are ex- 

 plained here: The Phanerophytes are the least protected, the buds 

 surviving the unfavourable season in the air. The surviving buds of 

 the Chamaephytes are on or near the surface of the earth, of the 

 Hemicryptophytes in the earths crust, of the Cryptophytes (Geophytes) 

 immersed in the earth. The Therophytes, annuals, survive onh' 

 as seeds. 



Now, taking the earth as a verhole the author has made up ap- 

 proximately the percentage of each type, and in comparing these 

 numbers with the corresponding ones from different countries, and 

 these again with each other he is able to draw Bio chores, biogeo- 

 graphical boundar5'^-lines. 



Thus, taking the tropical zone, v^e find the Phanerophytes pre- 

 dominant, giving a higher percentage than the "normal spectrum" 

 for the whole earth. But going towards the North we find that other 

 climates make other types predominate. 



From south to north the author follows two different series of 

 climates: 



1. ("B-series.") Heat decreasing towards the North, difference be- 

 tween summer and winter increasing, precipitation generali}^ favou- 

 rable for plant-life. This series is to be found in the eastern part 

 of the continents. 



2. ("C-series.") Heat decreasing as in 1, but precipitation also 

 decreasing, at any rate in summer-time. Farther North all is as 

 in 1. This series is characteristic for the western part of the con^ 

 tinents. 



A Statistical investigation of life-forms through eastern N.-Am er ica 

 gives the data characteristic for a "B. -series". In the West-Indies 

 Phanerophytes predominate, in Georgia and S.-Labrador Hemi- 

 cryptophytes, but in N.-Labrador, Baffinsland and Ellesmere- 

 land a higher and higher percentage of Chamaephytes accompany 

 the Hemicryptophytes. Therophytes are decreasing towards the North. 



On the other hand, a series of statistics through western 

 N.-America (a "C-series") shows the following features: as before 

 the Phanerophytes are decreasing towards the North, but instead of 

 having a Hemicryptophyte-cWmsite N. of them we find here a Thero- 

 phyte ■clima.ie (statistics from Death valley), the Therophytes being 

 the life-form best fitted for dry climates. N. of this we find the 

 Hemicryptophytes, which yet farther N. are accompanied by the 

 Chamaephytes^ as above. 



Quite a parallel series is given from the western part of the old 

 World. Here 19 statistics are given, from the Seychelle islands to 

 Franz Josephs land and Hope island, and here we have the 

 same zones as in western N.-America, also a subtropical zone cha- 

 racterized by Therophytes. 



In a special chapter the author gives a number of statistics from 

 the arctic countries. All show the same: towards the N. P/w«ero/)Ä3'/6?s 

 and Therophytes decrease in number and disappear, and the same 

 is the case with the Geophytes. The Hemicryptophytes on the other 

 hand have about the same high percentage everywhere. The Cha- 

 maephytes increase in number towards the N., at last reaching twice or 



