74 CHRISTISON—OBSERVATIONS ON 
and the prolonged effects on some of the trees, all of which is 
fully detailed in former papers.* Suffice it to say here that in 
1880, the worst year for the deciduous trees, their aggregate 
girth-increase was only half what it was in 1878, and that, while 
the Deciduous group reached their minimum of increase in 1880, 
the second of the three severe seasons, rallying very decidedly 
in 1881, the Pinacez continued to fall off in that season and did 
not rally till 1882. 
The second decade shows no such startling results, and the 
other seasonal fluctuations, considerable though they be, are 
probably only such as may be ordinarily expected in a climate 
so variable as ours ; but they are interesting as showing that the 
species were not all implicated in the same seasons of depression. 
The effects of increasing age seem to be pretty clearly indicated 
also. 
FAGUS SYLVATICA. 
AGGREGATE GIRTH-INCREASE IN FouR BEECHES FOR TWENTY YEARS. 
First Decade, .. .. | 1878. | 1879. | 1880. | 1881. | 1882. | 1883. | 1884. | 1885. | 1886. | 1887. 
Increase, = O | 2°85 | 1°95 | 2°75 | 3°35 | 2°90 | 3-45 | 2°85 | 3°10 | 2°60 
Second Decade, .. .. | 1888. | 1889. | 1890. | 1891. | 1892. | 1893, | 1894. | 1896. | 1896. | 1897. 
Increase, ze .. | 2°25 | 2°35 | 2°35 | 2°30 | 2°80 | 2°50 | 2-75 | 2°05 | 2°65 | 2-25 
These four Beeches girthed, in round numbers, five and a 
half, six and a half, seven, and seven and a half feet in 1897, and 
showed no outward sign of diminished vigour. The Table 
shows, however, that they never quite regained the standard of 
360 in 1878, the year preceding the three severe seasons, 
although twice, in 1882 and 1884, they very nearly did so. 
Their minimum, 1°95, occurred in the second bad season, and 
severe as the fall may seem, it was less than in any of the other 
deciduous species. The rally to 2°75 in 1881 and to 3°35 in 
1882 was so compiete that evidently no permanent injury had 
been done, and the subsequent gradual though fluctuating 
* ‘* The Influence of the ee Season of 1879 on the Growth of Trees.” 
By Sir R. Christison, Bart., Tr. Bot. Ed., 1880. 
‘The Growth of Wood in 1880.” By Sir R. Christison. Op. cit., 1881. 
“* The Depression in Girth Increase of Trees in 1879, 1880, 1881,” Dr. D, 
hristi cit., 1888-89, p. 
