134 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
It will be seen that both series of plots give consistently the 
same results. The largest number of plants was got when the 
seed was covered with soil to the depth of only } inch. When 
the covering was increased by another } inch, a large proportion 
of the plants never succeeded in struggling through the soil at 
all, the total number being reduced from 992 to 633, Further 
additions to the depth of the covering were accompanied by a 
steady reduction in the number of plants, until, when the seeds 
were buried to the depth of 1} inch, no plants whatever appeared 
above the surface. 
While these results indicate how careful one should be in 
regard to the depth of covering of spruce seeds (and no doubt 
the results might also be applied to other tree seeds of semilar 
size), they also show how extremely necessary it is to have 
the seeds actually covered, and not left lying exposed upon 
the surface of the ground. Where this method of sowing was 
practised, I obtained a total of only twenty-five plants, and 
this notwithstanding the fact that the seeds were thoroughly 
secured by a net against the attack of birds. 
How DEEP MAY ACORNS BE BURIED ! 
In the spring of 1894 seven rows in duplicate were each 
stocked with fifty acorns of uniform size, which were buried at 
depths varying from 4 to 6 inches. A year later the plants 
were counted, with the following results :— 
| 
| Number of Plants produced. 
Plots. z oie 
‘*A” Series. | ‘‘B” Series. | TOTAL. 
Inches. 
1 4 25 11 | 36 
2 1 32 31 63 
3 2 42 28 70 
4 3 27 26 | 538 
5 4 32 25 57 
6 5 18 14 32 
7 6 15 13 28 
| 
In this case the best results were got with a covering of 
2 inches, a depth which gave seventy plants per one hundred 
seeds.! 
1 The term ‘‘seed” is here, and elsewhere in the paper, used in the 
popular sense. 
