It was shown by Went7 that leaf growth in etiolated pea seedlings is primarily controlled by substances supplied from the cotyledons. Vein growth is controlled by auxin,2 while growth of the mesophyll is independent of auxin, and it is the factors concerned in the growth of the latter which we will discuss in this paper. In a recent paper3 a bio-assay for these factors was described in detail, ...

Growth substances are compounds of a hormonalnature which, although present in the plant in extremely low concentrations, govern the life of the plant. 1\-1:uch regarding these substances is still obscure. Until recently it was thought that the chemical structure of all c~mpounds with growth substance activity (both natural and synthetic) conformed to two essential requirements, but the members...

The action of growth substances in causing cell elongation is closely linked to respiration, and many respiratory inhibitors also inhibit growth (COMMONER and THIMANN, 3, BONNER, 1, 2). In the study -of the way in which growth substances act to bring about growth it is therefore useful to have inhibitors which will suppress the action of growth substances without affecting respiration of the tr...

In the study of bacterial symbiosis and antagonism, considerable interest has centered in the presence or absence of growth when organisms are reinoculated into filtrates of cultures of the same or different species. The nature of the substances which favor or inhibit the simultaneous or subsequent development of bacteria in the same nutritive medium has provoked much discussion and stimulated ...

Water potential is amongst the most useful parameters for the measurement of the degree of water stress in plants. With the objective of mitigating adverse effects of moisture stress on water potential, osmotic potential and pressure potential of wheat variety Inquilab-91, a greenhouse experiment was conducted using two moisture levels viz., normal moisture supply and moisture stress at crown r...