566 DEVELOPMENT OP THE N.O. MYRTACE.E, 



In this connection, it may be advisable to consider leaves, 

 stamens, anthers, and the habits of individuals. 



The leaves of Myrtaceae are typically opposite, glossy, broad, 

 penniveined, and dotted. In many Baeckeas, Darwinias, Kunzeas, 

 Verticordias, Chaniaelauciums, Melaleucas, Thryptomenes, Micro- 

 myrtus, and other types, the leaves are rigid, terete, and generally 

 depauperate in form. Such suggest development under harsh cli- 

 matic, or impoverished soil-conditions ; and such species are mainly 

 the younger forms of the genera which have accommodated them- 

 selves to the Post-Cretaceous and later Tertiary, or even Post-Ter- 

 tiary, conditions. 



The stamens of Myrtaceae are characteristically numerous, free, 

 long, and often brightly coloured. In Chamaelaucieae and some 

 Leptospermeae, the stamens are frequently much reduced in size 

 and number, and such condition is accompanied, as a rule, by 

 severe climatic and soil-environment. Those species of the genera, 

 thus affected, are apparently of more recent development than the 

 typical types of the genera. 



The typical anthers of the family are versatile, the cells parallel 

 and opening longitudinally. Thus the Angophoras and Corym- 

 bosas have the typical anthers of Myrtaceae, but the Boxes and 

 Ironbarks possess peculiar porose or truncate anthers, and the 

 Stringybarks, Peppermints, Messmates, Mountain-Ashes, and some 

 Mountain-Gums, possess kidney-shaped anthers. The Melaleucas, 

 Callistemons, Leptospermums, and Kunzeas possess typical anth- 

 ers, but Beaufortia, Begelia, Pileanthus, and Verticordia possess 

 peculiar varieties of porose and grooved anthers, and such peculiar 

 types, moreover, are endemic in Western Australia. Again, the 

 Baeckeas of Eastern Australia are mostly possessed of typical 

 anthers, whereas the majority of the species, endemic in Western 

 Australia, possess anthers very divergent from the type. 



These interesting facts, coupled with a knowledge of the geogra- 

 phical environments, indicate that those Eucalypts, Baeckeas, 

 Chamaelauciums, and Beaufortieae, with peculiar leaves and anthers, 

 are recent in proportion as they depart, in morphological charac- 



