84 TRANSACTIONS OF ROVAL SCOTTISH ARBORICULTURAL SOCIETV 



the "Thousand seed test." Various mechanical appliances 

 have been invented to sort the seeds in accordance with both 

 size and weight. Dr Busse, in experiments with Kayser's 

 centrifugal machine, obtained from an untreated supply contain- 

 ing 216,000 seeds per Kg. two classes, the best containing 140,000 

 seeds per Kg., the second 172,000 per Kg. This latter is 

 approached and sometimes equalled by the best trade supply. 



Haak, though he advises the use of selected seeds for the pro- 

 duction of planting material, considers the origin of the seed of 

 such preponderating influence that in open sowings he would con- 

 sider it waste to exclude the smaller sizes, as in accordance with 

 Engler's experiments the difference observed in the earlier stages 

 of the seedlings disappear in the course of a few years. The 

 hereditary influence of the parent tree, replies Dr Busse, is 

 undisputed and indisputable, but so long as the origin means 

 merely a definition of the locality whence the seed was obtained, 

 no guarantee exists regarding the characteristics of the individual 

 parent trees. Hoffrath Frederick found, in the course of years 

 of experience and experiments, that some of the trees under his 

 observation invariably bear heavier cones than others, and 

 produce heavier and larger seeds, and that the quality of the 

 plants raised from them is decidedly superior to those grown 

 from lighter seeds. That the elimination of the lighter seeds 

 would be an advantage can hardly be questioned, and if the 

 buyers insisted on a weight of 7 grs. or thereabout per 1000 

 seeds taken at random out of the supply, the trade would 

 unquestionably respond. 



The next step in the afforestation of the heather soils is the 

 planting up of the prepared areas with pines and Alnus inca7ia, 

 or the sowing where the soil is considered sufficiently ameliorated. 

 Fairly close planting or liberal sowings are advisable, for it is 

 essential to bring the sand soils as soon as possible under cover^ 

 in order to prevent the heather from regaining possession and 

 for various other reasons. The excellent results achieved in 

 Holland in similar afforestations are to a great extent due to 

 strict attention to close cultivation. 



The forester can now wait till the cover is completed and the 

 plants have thereby outgrown the dangers of infancy, but before 

 the struggle for existence sets in he must interfere and aid. In 

 regard to this a consensus of opinion exists among leading 

 scientists and the most eminent executive foresters. On rich 



