36o 



C. SKOTTSBERG 



the first to note the predominance of trees on oceanic islands, tried to explain 

 it as a result of natural selection. SiNNOTT and Bailey's criticism is absolutely 

 convincing. 



The authors also paid attention to The Ancient Flora of Antarctica, p. 592: 



It seems to be a reasonably safe conclusion that all genera commonly designated 

 as "Antarctic" from their confinement to the temperate region of the southern hemi- 

 sphere, were inhabitants of the ancient Antarctic continent. 



The authors made an attempt to reconstruct this flora and came to the con- 

 clusion that "two thirds of its endemic dicotyledons were woody plants" (p. 599). 



In the authors' opinion most of the herbaceous vegetation originated in the 

 north; this may be so because in the latter part of the Tertiary period, with the 

 increasing dififerentiation of climatic regions, the temperate and cold-resistant flora 

 is supposed to have taken possession of large areas, but these were concentrated 

 in the north; except the Antarctic continent there was not much land in the 

 far south. 



Several authors have expressed the same opinion as SlNXOTT and Bailey. 

 IrmsCHER [14^] was convinced that most of the primitive angiosperms were trees 

 and that the relation between tropical and temperate genera and species point in 

 this direction; to take one example: it is generally acknowledged that the her- 

 baceous, mainly temperate family Cruciferae descends from woody tropical Cap- 

 paridaceae (Irmscher might have called attention to the miniature Lepidiuui trees 

 in Hawaii): 



Auch sonst ist die Abstammung gemassigter Sippen von tropischen nachgewiesen 

 worden. . . . Diese Gegeniiberstellung der gemassigten und tropischen Sippen lehrt aber 

 auch ohne weiteres, dass mit der Anpassung von Formen an die extratropischen Zonen 

 zugleich die Umpragung des Typus des Holzgewachses in den des Krautes 

 vor sich ging, somit letztere als die jungeren Formen die Abkomm- 

 linge von H o Izge wjich se n sind (I. 2oq). 



Dass die Theorie der Abstammung der iibrigen Wuchsformen von der Gestalt des 

 tropischen Baumes immer mehr an Boden gewinnt, geht zum Beispiel aus dem Buche 

 von Bevvs hervor: "The megatherm hygrophilous forest of the tropics is probably the 

 most ancient tvpe of habitat . . . and most recent of all (life-forms) is the annual tvpe" 

 (II. 321). 



The investigation of Jeffrey and Torrey [14-i) led to the conclusion that 

 "the origin of the herbaceous type in Dicotyledons is from woody or arboreal 

 forms", and Stockwell, in his monograph of Chacnactis {2^g\ Compositae, 33 

 sp.), states that, "within a family or genus, woody perennial species are more 

 primitive than herbaceous annual species". An evolution in the reversed direction 

 is, however, postulated by HUTCIIIN.SON [140. I. 4) in the Polycarpicae. He regards 

 the herbaceous Ranunculaceae as the most primitive; a woody structure is, in this 

 order, secondary. The current opinion is that the woody IMagnoliaceae are among 

 the oldest living angiosperms. 



llie rosette trees. — The common type of this interesting growth-form is char- 

 acterized by a candelabrum-like mode of branching, the two or three (rarely more) 

 innovations situated on practically the same level at the base of a terminal in- 



