ch.ix COMBINATION OF SYSTEMS 223 



Artificial regeneration can make possible the em- 

 ployment of the methods of clear -fellings, which are 

 otherwise not often possible with only natural regenera- 

 tion to depend on. Whether direct sowing or planting 

 would be resorted to would depend on circumstances ; 

 but, more generally in the Tropics, the area would be 

 planted over, as, in this manner, the soil would be covered 

 quicker and there would be less danger from deteriora- 

 tion of the soil and from invasion of weeds. In poor 

 soils and in exposed situations this method of clear- 

 fellings, followed by artificial regeneration, would be too 

 risky to be employed, and the same may be said of 

 places which are quickly covered by a network of 

 creepers, not only woody but herbaceous, such as several 

 of the Cucurbitaceae, Convolvulaceae, etc., which quickly 

 ascend into, bend, and stifle the young trees, and the 

 keeping down of which would be an endless trouble and 

 expense. 



Where this operation is permitted, the necessary 

 mixture of species can be given, either by sowing or by 

 planting ; as regards the former, either by thoroughly 

 mixing the seeds beforehand if they are more or less of 

 the same size, or by sowing them in different rows if 

 they vary in size. A start may be given to any indi- 

 vidual species by sowing it first, and sometimes by givino- 

 the seed a special preparation. In planting, the exact 

 mixture required is even more easily given, and a start 

 to any species can be given either by planting it first or 

 by putting in stronger transplants of that species. 



In most forests will be found blanks which are too 

 large to be naturally regenerated, pari passu, with the 

 rest of the forest. In these, artificial regeneration has 

 to be employed in order to effect this. 



Artificial regeneration is also employed to assist 

 natural regeneration fellings where the result is a patchy 

 or irregular crop of seedlings, or where a new species has 

 to be introduced, or where special encouragement is 

 required for one of the species which may be repre- 

 sented among the seed-bearers but not abundantly, or 



