HARDWICKIA 357 



of Cassia auriculata, Gymnosporia montana, and Rhus parvi folia are of great 

 use in regeneration : it is surprising how many healthy Hardwickia seedlings 

 one finds right under the shade of such bushes : this is apparently due to the 

 shelter afforded from the heat of the direct sun's rays and to the fact that 

 under such bushes there is an accumulation of soil and humus ; also where 

 cattle grazing is allowed such bushes protect the seedlings from being eaten. 

 I have not yet come to a conclusion as to whether such bushes should be cut 

 level with the ground when the Hardwickia seedlings in their shade have 

 attained a certain age.' 



5. Climatic factors. We have already considered at some length the 

 adverse effects of drought on the development of the seedling and the establish- 

 ment of natural reproduction. The factor of rainfall is one which seems to 

 require further study, and in this connexion the following quotation from the 

 Yerramalais working plan ^ is of interest : 



' Most of the seedlings die out in the prolonged drought which follows 

 the rains and continues for about nine months. It is only when this drought 

 is interrupted by rainfall that some of them survive. Therefore it is usual 

 to come across a group of youilg seedlings in one place and a patch several 

 years older at another. For successful regeneration rainfall should be regular 

 or the seedling sh6uld be able to pass the strata affected by drought before 

 it is killed.' 



The extent and distribution of the seasonal rainfall may very well be 

 presumed to have an effect on the establishment of natural reproduction ; in 

 the absence of direct evidence, however, it seems unsafe definitely to ascribe 

 the establishment of reproduction in patches to favourable years of rainfall, 

 though it is by no means an improbable explanation of the phenomenon. 



Conclusions. From the details just given it may be concluded that, given 

 the necessary seed-bearers, factors ordinarily beneficial to the establishment 

 of natural reproduction are porosity and depth of soil, protection in early 

 youth from the heat of the sun, protection from fire and grazing, and probably 

 also favourable rainfall conditions. Adverse factors are stiffness and shallow- 

 ness of soil, exposure of the seedlings to a hot sun, fire, grazing, and probably 

 adverse rainfall conditions. Under certain conditions a soil-covering of grass 

 may be decidedly beneficial in affording protection from the sun, while under 

 other conditions it may, if sufficiently rank, be a highly noxious factor in 

 preventing the seed from reaching the ground and in suppressing seedlings or 

 causing them to damp off. 



There may possibly be other factors affecting the question, but those 

 under consideration give some indication of how natural reproduction may 

 be induced, namely, by ploughing or hoeing up the ground to the leeward 

 of seed-bearers in good seed-years and protecting the resulting seedlings from 

 the heat of the sun. In Nimar, and no doubt in other localities, this protection 

 can be secured, according to Mr. Witt's observations, by allowing the grass 

 to grow up ; under some conditions, however, it may be necessary to keep 

 the soil loose and to clear the grass. In either case the shade afforded by 

 trees and bushes will be beneficial and may even be essential. This last con- 

 sideration gives a possible clue to the origin of some of the existing crops 

 1 Working Plan for the Yerramalais, West Kurnool, J. Tapp, 1913. 



