550 DEVELOPMENT OF THE N.O. MYRTACE^E, 



The true Eugenias appear to have been developed in Central 

 and tropical South America, and these underwent parallel trans- 

 formations with the Myrtles, into the Myrcias, Psidiums, Campo- 

 manesias, Calyptranthes, Myrrhinums, Blephserocalices, Myrierias 

 and other types. In all these forms, one may note the similarity 

 of the types evolved, a similarity suggestive of the continuity of 

 fertile and tropical conditions. In Asia, Jambosa and Syzygium 

 are the representatives of Eugenia, but in their geographical dis- 

 tribution, in their inflorescence of trichotomous cymes or panicles, 

 and in their petals more or less cohering in calyptra, it would 

 appear advisable to include Jambosa and Syzygium under genera 

 separate from Eugenia. 



In studying the various types of Eugenia, Jambosa, and Syzy- 

 gium, one notes, at times, the peculiar sessile, opposite and some- 

 what cordate leaves, which suggest the peculiar juvenile leaves of 

 certain seedling Eucalypts. Syzygium propinquum, in addition, 

 has a venation suggestive of the corymbose Eucalypts. In one 

 species, at least, of Eugenia, again, the buds are strikingly sugges- 

 tive of certain Eucalyptus- types, while strong intramarginal veins 

 are not uncommon in some Eugenias. The absence of Myrtus and 

 Eugenia in Europe and extra-tropical Asia, with the exception of 

 Myrtus communis in Southern Europe and Western Asia, and the 

 almost complete absence of these genera in Patagonia, Southern 

 Chili, the Argentine, and the United States of America, as also 

 their absence in Southern Australia, except for Eugenia {Syzy- 

 gium) Smithii in Victoria, indicates unmistakably that the Myrteae 

 have not been enabled to adapt themselves to cool, temperate condi- 

 tions, especially in a direction northwards, in the face of the ag- 

 gressiveness of the Scandinavian flora. It is a rather remarkable 

 fact that Eugenia (Syzygium) Smithii is the one species, at least 

 in the Eastern Hemisphere, which possesses kidney-shaped anthers. 

 The presence of 40 species of the genera Jambosa and Syzygium 

 in Australia, suggests that these genera entered Australia, or at 

 least the southern portion of what is now the Malay Archipelago, 

 in Cretaceous time, and that they are ill-adapted to compete with 

 the endemic flora under existing geographical conditions. 



