278 C. SKOTTSBERG 



my discussion with F. H. H. l^Rowx [jji] made Croizat remark that "the debate 

 proved futile, as could be anticipated". To attempt a solution and to discuss possible 

 routes of mi<i;ration is called "obvious nonsense". 



Of the presumable history of liupJirasia enough has been said above. In Croi- 

 ZAl's opinion there cannot be the cjuestion of a north-south track from Asia across 

 Malaysia to Australia and New Zealand; his map fig. 6 shows the centre far south 

 in the Pacific, from where tracks lead east to S. America and west to New Zea- 

 land and Australia and thence from there to Eurasia and along the Aleutian arc to 

 N. America. 



I'rom the lu'pothetical "main angiosi)ermous center" south of Madagascar, 

 where Plantao^o-Pa/afopsyl/iii/fi was born, one branch leads west around S. America 

 to Juan Fernandez, another east to Polynesia and from there to Hawaii, alterna- 

 tively reached directly from Juan P^rnandez. I preferred the first alternative, but 

 even if the circumpolar distribution suggests an Antarctic origin I can see no good 

 reason to place the starting point south of Madagascar. 



Copros))ia is one of the standard Antarctic dispersal types but lacking in Africa 

 and in continental America. P>om its distribution Croizat draws the following 

 conclusions. 



This dispersal shows a) An Antarctic range in the southern Pacific which fed Co- 

 prosma to all lands between Juan Fernandez and E. Java, b) This range could possibly 

 reach Hawaii from West along the line East Malaysia-Hawaii, c) The trend of this type 

 of disj)ersal is all westward from the Americas (Juan Fernandez to New Zealand, Aus- 

 tralia, New (iuinea, Malaysia) ultimately veering again eastward to reach Hawaii (p. 101). 



To make Juan P^ernandez the source of Coprosnia in New Zealand is utterly im- 

 possible and the statement is not in agreement with Croizat's map, fig. 29, which 

 shows a baseline along lat. 60° between the longitudes of New Zealand and Fuegia 

 and arrows pointing west to New Zealand and northeast to Juan F'ernandez. 



1 am not going to enter upon a discussion of the origin of a world-wide family 

 like Com{)ositae; I shall only quote the following sentence: "The perfect circum- 

 [)olar distribution of I'araxacuui viagellanicuin ... in itself tells us where is to be 

 sought the ultimate origin of the Compositae" (p. 63). Even if it is true that this 

 interesting dandelion also inhabits New Zealand, the conclusions would seem too 

 far-reaching. 



I shall conclude this discussion with a summary of a recent paper by AXELROD 

 (/■r) who gives us a palaeontologist's view on angiosperm evolution. 



The cradle of angiosperms stood in the tro})ical belt, the width of which has 

 undergone considerable change during the geological ages. The angiosperms origi- 

 nated and evolved in uplands during Permian to Triassic times and gradually 

 descended to the lowlands to replace the vanishing floras now extinct or repre- 

 sented by such remnants as the Cycadophyta. P\)ssil records, especially of pollen, 

 make it probable that many families existed in early Jurassic, and from middle 

 Cretaceous, when angiosperms had gained dominance over gymnosperms and ferns, 

 the presence of numerous families belonging to very different orders bear witness 

 of a long history. By that time three different lowland floras had developed, the 



