396 E. C. ANDREWS. 
however, to the inhospitality of the extensive wastes of 
sandy soil, and sub-arid climate, by the suppression of the 
bipinnate leaf in the adult stage and the adoption instead 
of the phyllode. The phyllodineous Acacias thus developed 
may be divided into two series, namely, those whose 
phyllodes possess one strong central nerve with reticulating 
venation, and those whose phyllodes possess two, or more, 
parallel nerves. To these Bentham gave the names Uni- 
nerves and Pleurinerves respectively. Both series possess 
flowers in globular heads. To those Acacias with pleuri- 
nerved phyllodes and flowers in cylindrical spikes, the same 
botanist gave the name Juliflore. The geographical dis- 
tribution suggests that Uninerves, Pleurinerves, and Juli- 
 floree, alike, originated in North Australia and that the 
occupation of the temperate portions of Australia, and 
Tasmania, by these types took place at a later date. 
The Uninerves are most numerous in temperate, while the 
Pleurinerves and Juliflore, especially the latter, are densest 
in tropical Australia. It is possible that the Uninerves 
and Pleurinerves originated independently of each other, 
the former favouring the southern, the latter the warmer 
portions of the continent, because the abolition of leaves, 
and the development of either phyllodes, cladodes or spines, 
is not uncommon in other Leguminose, such as Cassia 
phyllodinea, C. circinata, Notospartium, Corallospartium, 
Carmicheelia, Bossizea, Daviesia, Jacksonia, and Viminaria. 
With the idea of ascertaining the possible priority of either 
the Uninerves or the Pleurinerves, Mr. R. H. Cambage has 
grown several forms of Acacia. The results were incon- 
clusive, nevertheless enough information was secured to 
indicate that the earlier phyllodes of these types were 
narrow, consisting of a slight flattening of the petiole and 
the development later, at least in A. melanoxylon, of lamina 
with the production of nerves slightly concave to the main 
nerve, being confluent also with the latter at each end of 
