Australian Flowering Plants. 193 



it is proposed to discuss the probable distribution of the 

 Leguminosce, Myrtacece, Rutacew, Euphorhiacew, Veroenacew, 

 LabiaUe, Sterculiacece, Sapindacew, Pittosporacea?, Trenian- 

 dracew, Malvaceae, Apocynacece, Asclepiadacea?, and other large 

 groups. 



It would be beyond the scope of the present paper to deal 

 with these great families in detail and the remarks herein will 

 be confined, therefore, to the salient features of distribution 

 in a few of the larger divisions of the families. 



(2) Leguminosce. 



It seems safe to conjecture that 14 during the Cretaceous, or 

 the Eocene, or both, the tribes of the Mimosacese, Csesal- 

 piniacere, and Papilionacese, now mainly confined to the tropics, 

 were scattered over the greater part of the world, Australia 

 being joined to Asia, and all the great land masses being con- 

 nected directly within areas of mild and moist climate, although 

 not at all necessarily, within the present tropical or subtropical 

 regions. 



The tribes which do not appear to have been in existence 

 during the Cretaceous were the Trifoliese, Lotese, and Vicieae. 



It may be permissible, moreover, to infer that during this 

 stage the great tribes such as Sophorese, Cassiese, Acaciese, 

 Galegese, Phaseolese, and Genistese, were abundantly repre- 

 sented mainly as trees of luxuriant habit, although the acacias 

 and to a less extent the cassias suggest even in that remote 

 period either the existence of a great climatic differentiation 

 or of the existence of subarid, to arid, areas, or of waste open 

 spaces. It may be mentioned in passing that similar evidence 

 of the existence of xerophytes at this stage in flowering plant 

 development is yielded by a study of many other great families, 

 such as the Campanulacese, Lobeliacese, ITmbelliferee, and 

 Compositse. These tribes existed probably in all the great land 

 blocks, Europe and Australia included. 



The case of the Sophorese may be considered at this stage. 



During the zoning of climates, the regions of mild and moist 



climate gradually retreated from the higher latitudes toward 



the Equator, but as the change was accomplished very slowly, 



the plants had a long period in which to save themselves from 



extinction by the adoption of various devices against the 



increasing rigor of their environment. This factor of time 



as an ever-flowing quantity must ever be kept in view in the 



consideration of angiospermous development. The changes 



14 E. C. Andrews, The Distribution and Development of the Leguminosse, 

 Proc. Roy. Soc. N. S. Wales, vol. xlviii, 1914. 



