TRANSACTIONS OF SECTION K. 573 
may occur in the germ-cell and produce the dicecious form, or it may occur during 
flower bud differentiation and produce the monecious condition, or it may be 
delayed to a later stage when the sex organs are differentiated on a common 
floral axis. The hermaphrodite flower is then formed. The actual disposition 
of the male and female sex organs may also follow one of two types: (a) Female- 
ness central and terminal and maleness peripheral and lateral, as in many in- 
florescences and probably all hermaphrodite flowers; (b) Maleness central and 
terminal and femaleness lateral and peripheral, as in many inflorescences of the 
moneecious type and in some abnormal Begonia flowers. The type assumed, 
primarily female or primarily male, will depend on the position taken by the 
factors for maleness and femaleness respectively during the differentiating cell 
division, and on which factor passes into the terminal and which into the lateral 
daughter cells. 
The Bearing of these Facts on Plant Evolution. 
The monecious condition is probably an intermediate and unstable stage. 
The hermaphrodite flower (which is probably the result of necessity for 
adaptation to insect fertilisation) has been brought about by delaying the segre- 
gation of the g and @ sex organs till the period of the development of the 
flower. Probably also some hermaphrodite plants may have accelerated the pro- 
cess of sex differentiation. If this occurs early during the evolution of the inflor- 
escence such plants would revert to the monecious condition. 
In animals postponement of the process of sex differentiation from the germ- 
cell to the zygote stage also produces hermaphroditism. Certain abnormalities 
in the distribution of secondary sex characters in the higher animals suggest 
that the development of the individual organism proceeds along two main lines, 
a segmental and a bilateral line. Lateral and segmental gynandromorphs are 
thus produced. 
The Secondary Sex Characters of the Flowers of the Monecious Begonia. 
The two processes of qualitative cell division which result in (1) the differ- 
entiation of the g and Q primary sex organs, and (2) the differentiation of the 
secondary sex characters, are less intimately interdependent in plants than in 
animals. This greater independence may depend upon the absence of, or the 
very restricted circulation of, internal secretions or sex hormones in the case of 
plants. 
3. Some Account of the Flora of the Northern Territory. By ALFRED 
J. Ewart, D.Sc., Ph.D., and Outve B. Davies, M.Sc. 
As is well known, the Commonwealth Government, since taking over the 
Northern Territory, has carried out a policy of energetically investigating the 
natural resources of this tract of country. 
In addition to the expedition by Gilruth and Spencer, the Barclay expedition 
traversed a large part of the Territory, and Mr. Hill, the collector attached to 
the party, made large collections of plants. 
Dr. A. Morrison was appointed to assist in the work of investigating these 
collections and the flora of the Territory generally. In July 1913 he published 
a Paper with Professor Ewart, ‘ Contributions to the Flora of Australia,” 
No. 21: ‘The Flora of the Northern Territory (Leguminose).’ Unfortunately, 
before he could publish anything further he became seriously ill, and died in 
December 1913. 
Miss Davies was appointed successor to Dr. Morrison, and began work in 
February 1914. 
Mr. Maiden has undertaken the investigation of the Myrtacee and of the 
Acacias, in which groups his knowledge is unrivalled. 
The present Paper not only gives much additional information as to the 
distribution of the plants in the Territory, but includes several new species : 
among which are four new species of Leguminose, Jsotropis argentea, Ewart 
and Morrison; Jacksonia anomala, Ewart and Morrison; Psoralea luteosa, Ewart 
and Morrison; 7’ephrosia pubescens, Ewart and Morrison; two new species of 
Proteacee, Hakea digyna, Ewart and Davies; and Hakea intermedia, Ewart and 
