4 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



low elevations ; and that large seed produces large plants may 

 be at once admitted. Table I. shows that when the seed was 

 passed through sieves and sorted out into " large," " medium," 

 and "small" grains, the resultant plants, when two years old, 

 were always slightly tallest and heaviest when the largest seed 

 had been used, and shortest and lightest when the smallest 

 seed had been sown. But this does not explain why seed from 

 a high elevation, when sown at a lower level, produces com- 

 paratively small plants ; for the same result is got when seed has 

 been sorted, and when the comparison is with grains of exactly 

 equal size. The Table shows that in the case of unsorted seed, 

 gathered at altitudes varying from 1800 to 5950 feet, and sown 

 in 1899, the two-year-old seedlings averaged 5-3 inches in 

 height, and weighed 25 oz. per 1000 when the seed came 

 from mother-trees growing at the lower level, but only 2 inches 

 and 10 oz. when the mother-trees had stood nearly 6000 feet 

 above the sea. The Table also shows a gradual transition 

 from the big to the little seedlings, according to the elevation 

 of the seed-trees, but in inverse proportion, that is to say, the 

 higher the elevation of the seed-trees the shorter and lighter 

 the resulting plants. The character, it will be seen, is preserved 

 by the seedlings when they are five years old — at that age the 

 plants from Winterthur seed being 18 inches high, and 15 lbs. 

 in weight per 100; whereas plants raised from Engadine seed 

 were at that age only 9 inches high and 5 lbs. per 100 in weight. 

 The more important results of the Austrian experiments with 

 spruce are brought together in Tables II. and III. In the former 

 of these Tables figures are shown dealing with seed from three 

 different localities, and from three different altitudes in each 

 locality. This seed was gathered in the autumn of 1890, and 

 was sown in 189 1 in a nursery in the Wienerwald, near Vienna, at 

 an altitude of 1650 feet. When sufficiently large the plants were 

 set out in the forest, and the measurements for 1905, shown in 

 the Table, refer, of course, to the fifteen-year-old plants. Here, as 

 in the Swiss experiments, seed from high elevations usually 

 produced plants whose growth is slow, so that from seed gathered 

 at Kiirnten, at an altitude of 1700 feet, the plants were 53 inches 

 high, whereas when the seed came from 5200 feet in the same 

 district, the fifteen-year-old plants were only 30 inches high. 

 Similarly for the seed from South Tyrol and the south of France, 

 except that in the case of seed from the middle altitude in the 



