660 TRANSACTIONS OF SECTION M, 
gradually inferior, and finally barren as sea-level is approached, except for 
narrow strips along the high-lying arterial waterways. 
Canals such as these, though sometimes following a tortuous course, are 
always the most satisfactory, firstly because they easily command the country 
they serve with irrigation water, and, secondly, because the evils of salt- 
accumulation consequent on active infiltration are reduced to the lowest possible 
minimum. Conversely, drainage channels are not fully efficient unless they 
follow closely the lowest parts of depressions between opposing elevations. 
In Egypt differences of level are usually comparatively small; nevertheless, re- 
modelling of water-channels, which in the old days were not excavated according 
to the contours, has formed part of the irrigation programme since the British 
occupation of that country. 
It is understood that some Australian irrigation projects have not been 
entirely successful owing to difficulties such as are indicated, and it is urged 
that it is an economy to spend money on detailed mapping of new country before 
launching on projects of canalisation, which if lacking in finality may entail a 
greater outlay on remodelling than would have been needed for the initial survey. 
‘When we mean to build, 
We first survey the plot, then draw the model.’ 
(iv.) Irrigation in Victoria. By J. H. Derurinar. 
SYDNEY. 
ERIDAY PAC GOST 21. 
The following Papers were read :— 
1. Migration of Reserve Material to the Seed in Barley considered as a 
Factor of Productivity. By E. S. Braven. 
With barley the ratio of the dry matter accumulated in the seed to the total 
dry matter of the plant when fully ripe frequently influences the produce of 
grain to a greater extent than any other factor; also it is more important in 
barley than in either wheat or oats, because the value of the dry matter of the 
haulm (i.e., the stem and leaves) is less with barley; also this ratio is higher 
in some races of barley than in any variety of the other cereals, and probably 
higher than in any other cultivated plant. The paper dealt with some of the 
bearings of these facts. 
This ratio varies considerably as between different varieties of barley and 
as between different races of the same variety of any cereal species. It has a 
high value for purposes of selection, especially in the early stages of selection 
from amongst a limited number of individual plants which are the progeny 
obtained by the artificial cross-fertilisation of any two individuals. 
As between two races, each the progeny of a single plant of the F4 generation 
of the same cross, and with the same weight of dry matter in the entire plants 
on unit area, the inherited and persistent difference in the ratio referred to has 
been found in a series of experiments to be as much as 5 per cent. In conse- 
quence of this factor alone with the same total weight of grain and straw on unit 
area the yield of grain was more than 10 per cent. greater in some such races 
than in others. : 
In the case of hybrid races generally the number of individuals possessing 
different combinations of characters is very large, especially if minor characters 
affecting either productivity or quality are taken into account. The experi- 
mental error involved in selecting either individual plants, or aggregates which 
are the progeny of single self-fertilised plants, for the purpose of starting new 
races of cereals is so great in consequence of environmental conditions that no 
conclusions of practical value can be drawn, except from a very large number of 
observations, as to relative productivity when only the dry weight of the grain 
is taken into account, and then only if special methods of cultivation are 
adopted. 
