76 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



the most suitable type, and the results seem to have been very 

 satisfactory. 



Given a stock of trees of suitable geographical type or form, 

 we have next to select the most favourable locations as regards 

 soil and climate for each species. 



This cannot be done with accuracy unless we know the 

 conditions of soil and climate in the native habitat of the desired 

 type of any species. Control of seed importations is desirable, 

 but this cannot be done with advantage until we know definitely 

 what we want to control. Therefore, like the Norwegians, we 

 should first study all the growth factors in the native habitats of 

 the types of species we desire, and having found the best types 

 the next thing is to obtain seed from localities where growth 

 factors most nearly approximate to those in our own country, 

 and the best way to do this is to send a man who knows the 

 conditions in this country to study the trees in their native 

 homes. In general practice we consciously or unconsciously 

 apply processes of selection and elimination in the rearing of a 

 crop of timber. First the seed is tested for purity and germina- 

 tion. Next the seedlings are culled and assorted in the lining- 

 out process in the nursery. Again when transplants are lifted 

 the weaklings are rejected and the material is classified, and 

 each class is assigned to an appropriate planting area. The 

 process of selection is continued throughout the thinning period. 

 Hence the trees which form the ultimate crop have been under- 

 going a process of segregation from their earliest stages of 

 existence This is no doubt as it should be, but do we begin 

 selection at the right stage? I would suggest that we should go 

 a step further back and select seed in suitable localities and 

 from the best type of trees ; otherwise if we begin with seed of 

 an inferior type of tree, no matter though its germination 

 capacity may be high, we can never by any conceivable process 

 of subsequent selection of individuals produce a growing stock 

 of a quality equal to what might have been possible if seed of 

 the right type had been used. But even though it is possible to 

 form plantations under these conditions, it is still necessary to 

 keep a constant lookout for the first signs or symptoms of 

 unhealthiness, in order that the disturbing cause may be ascer- 

 tained and appropriate counter-measures adopted. 



In the case of actual disease the usual method hitherto has 

 been to pay no attention to the loss of a few plants, and the 



