486 BOTANICAL GAZETTE [yuNE 
From the character of cretaceous climates this or some other 
theoretical prototype flourished in a mesophytic environment. 
Among modern groups the nearest approach to this theoretical 
stock is furnished by the Myrtoideae which are fleshy fruited, 
most numerous in species, and widely spread in the equatorial 
regions of the world, with over 75 per cent, however, confined to 
America. The existing Myrtaceae with capsular fruits, represent- 
ing the extreme of specialization in the family are Australian, while 
the Chamaelaucieae, standing in an intermediate position between 
the two preceding groups, are almost wholly confined to Western 
Australia. 
These are the facts of modern distribution. Their interpreta- 
tion may be various. ANDREWS (op. cit.), from a study of the 
present distribution, geologic climates, and the geological history 
of the Australian region, concludes that the Leptospermoideae 
originated from the Myrteae, and that the cretaceous forms were 
widespread, which latter was undoubtedly the case. He is con- 
vinced also that before the separation of Australia from the Asiatic 
mainland fleshy fruited forms found themselves in a region of warm 
moist climate, but relatively poor soil, and that it was this edaphic 
factor that was the principal stimulus to the differentiation of the 
Leptospermoideae, which with the exception of the genus Metro- 
sideros Banks show adaptations to poor soil and temperate or dry 
climates, and this exception explains the relatively wide distribu- 
tion of Metrosideros from Asia to the Fiji Islands. The Eucalyptus 
forms, according to the view of this student, were derived from 
Metrosideros after the separation of New Caledonia from Australia 
and the latter continent from Asia. To support this latter point 
ANDREWS is obliged to consider all of the cretaceous identifications 
of Eucalyptus and all of the tertiary identifications outside of 
Australia as equally misleading. With regard to the presence of 
Eucalyptus in North America I think this contention to be not 
unlikely, for although in accordance with paleobotanical usage 
I have identified numerous forms of Eucalyptus in the North Ameri 
can Upper Cretaceous, I have long thought that these leaves repre- 
sented ancestral forms of Eugenia or Myrcia, but have hesitated 
suggesting any change based merely on personal opinion and also 
