•_'is E. ('. Andrews — The Geological History of tin 



(Clermontia ll species, Rollandia 6 species, Delissea 7 species, 

 Cyanea :>S species), the arborescenl Scelerotheca of Tahiti and 

 Etaratonga, Apethia of Raiatea, the remarkable tree Tjobelms of 



Hawaii. Ahvssinia, and Central Africa, and the arborescent 

 forms in America, it. would appear that the early forms were 

 trees which loved moist open spaces, the trees possibly without 

 milky juice. 



In the Cretaceous Period the primary types found their way 

 into Australia, and during the first differentiation of climate, 

 probably during the Cretaceous Period, the arborescent types 

 became more and more herbaceous and found their way into 

 Australia, South Africa, and other countries, as the genus 

 Lobelia, and allied forms. The ancestor of Campanula- and 

 WaJilenbergia also found its way round the world about this 

 period. 



The oldest forms have produced the remarkable and special- 

 ized Goodeniaeeas and Candolleacea? which arose in Australia 

 on the barren, sandy wastes, after the great isolation of Aus- 

 tralia and after great modifications had taken place in the 

 stigma and filaments of the primitive type in Australia. In 

 the northern hemisphere the ancestral types were driven out 

 and all that we know of the middle era of the race after the 

 differentiations into Campanulacese and Lobeliaceae with milky 

 juice, are the peculiar arborescent genera above mentioned, 

 which are not actually perpetuations of old time genera, so 

 much as they are newer genera allied to the older LobeliaceaB 

 and which have been evolved locally in response to their later 

 environment of sandy waste in the peculiar climate of 

 Australia. 



After the isolation of the northern hemisphere and the cli- 

 matic differentiation of post-Eocene time, Campanula appears 

 to have been developed in the north, and Wahlenbei-gia in the 

 south. The latter became aggressive and penetrated the north 

 at a later date much in the same way as Erica had done among 

 the heaths. 



The Goodeniacea? with an indusium to the stigma and the 

 Candolleacese with filaments and and pistil united into a column 

 appear to be magnificent examples of ancestral types which, 

 after retreating as arborescent forms from more favored sur- 

 roundings in the north to a "dead end" in Australia, gradu- 

 ally developed the herbaceous habit on sandy and stony wastes 

 which were subject to long, dry, hot spells. In the fullness of 

 time these became hardy, vigorous, and aggressive types which, 

 like ~\Y alilenbergia and Lobelia of older and more northern 



