DEVELOPMENT AND DISTRIBUTION OF THE LEGUMINOSZA. 391 
the old world about the time that the xerophytic Genisteze 
and Podalyrieze were being developed. 
PHASEOLEA.—This in the main, is an old and tropical 
tribe which has not adapted itself readily to temperate 
climes and inhospitable surroundings. Genera such as 
Rhynchosia, Hriosema, Phaseolus, and Erythrina, exist in 
all tropicalregions. None occurin New Zealand. Peculiar 
endemic genera of Phaseolez in Australia include Harden- 
bergia and Kennedya. 
DALBERGIZ.—A tribe almost completely tropical, most 
of whose members are of luxuriant types, which is repre- 
sented in Australia by an endemic species of Dalbergia. 
None occur in New Zealand. Several stragglers occur in 
South Africa. It is specially abundant in the American 
tropics. 
It appears to be a tribe with specialised stamens and 
fruits which originated during a period considerably post- 
dating the development of the Sophore, the Genistez, and 
Galegee. 
Families CAESALPINIEZ and MIMOSEA. 
Cassia and Acacia are types respectively of Caesalpinieze 
and Mimosez. They are analogous to genera such as 
Indigofera, Crotalaria, Pithecolobium,! Tephrosia, and 
Rhbhynchosia in Leguminose, as also to Myrtus in Myrtaceze 
in that the uniform, and less specialised types are widely 
diffused throughout the tropics, while the specialised or 
secondary types have been developed locally along variable 
lines in different regions outside the tropics. These special- 
ised forms of divergent nature in contrasted regions are 
mainly xerophytic. It is proposed to mention a few of the 
characteristic features of Acacia as being typical of the 
development of the two families under consideration. 
1 The leaves of Acacia and Pithecolobium, however, suggest a more 
recent differentiation than forms such as Crotalaria and Rhynchosia. 
