72 . CHRISTISON—OBSERVATIONS ON 
nearly an inch and a half for three years; then come the Cherry, 
Beech, Sycamore, and Poplar with about an inch and a quarter, 
and the American Oak, Ash, Birch, and Hawthorn with about 
an inch. At the other end of the scale are Alder and Hornbeam 
with three-fourths of an inch, Robinia, British Oak, Rowan, 
Laburnum, Pear, and Lime being slightly better than that. 
Annual range—Naturally this tends to be greatest in the 
trees that were longest under observation ; but even confining 
ourselves to the seventeen which had from five to nine years’ 
records the range is not great. In ten the maximum was less, 
sometimes much less, than double the minimum; in six it was 
only rather more than double; and in only one was it extreme, 
being three and a half times greater than the minimum. This 
was the Hawthorn, No. 19, a very infantile specimen, and in the 
slightly older No. 11 the range was quite slight. 
aximum single years tncrease—Only three of the twenty- 
three trees failed to attain one inch of increase in one or more 
years ; these were the Pear, with 95 ; Alder, No. 7, with 85; and 
Evergreen Oak, with 85. But another Alder, No. 88, attained 
120. The highest results were—Willow 2°80, Wych Elm 1°75, 
Poplar 1°75, Hawthorn 1°65. 
II. TREES BETWEEN 15 INCHES AND Two FEET IN GIRTH. 
Annual rate.—Of the twelve trees, belonging to eleven species, 
admissible to this category, eight have already figured in the 
infantile period. The Willow reappears with the very high rate 
of 3:21 for three years. The Cherry now takes second place with 
1°80, and Wych Elm follows with 1°70; but the Birch, and the 
two new comers of Quercus conferta, are also above an inch and 
a half, and Acer campestris, at the bottom of the list, averages, 
along with Lime, Ash, and Horse Chestnut, about an inch and a 
quarter. 
Annual range—This is much less than in the infantile period. 
In no tree is the maximum double the minimum , generally it is 
considerably less, and only in Acer campestris does it come 
perilously near as much. 
Maximum single year’s increase—W illow again far and away 
heads the list with no less than four inches in a single year. 
Cherry is the only other that attains even two inches, although 
