116 CHRISTISON—OBSERVATIONS ON 
With regard to Quercus robur, for the reasons given in its 
history I have rejected the tree of 1891-95 and adopted the 
average of the four young Oaks of 1887-91, as being much more 
likely to be truly representative. As the defaulter has been trans- 
planted to properly prepared ground, it will be interesting to see 
whether it will now fall into line with the others.* The erratic 
conduct of the representatives of Pyrus, Alnus, and Cytisus 
defies explanation, and there was nothing for it but to take their 
combined averages for both periods. In 77/ia the difference is 
rather of degree than kind, but is so extreme as to shut it out 
from the reliable list. It is probable enough, however, that the 
united average, which I have given, is fairly representative. 
Carpinus was not observed in 1892-95, but the two young trees 
of 1887-91 did not agree well, and were in total disagreement 
with an old tree. 
(b.) The distribution of the girth-increase over the growing 
season seems to be most extended and equable in Cytesus 
Laburnum, and confined within the narrowest limits in 7Z7/za 
europea, in which three-fourths of the whole took place in two 
months. 
(c.) Progress of girth-increase from month to month. — 
In none of these species, except Quercus robur—and that in a 
less degree—was there a check in the rise and fall such as was 
noticed in Quercus conferta of the previous set. In three of them 
the movement was of an average kind, but in Quercus robur a 
very marked rise in July, and in 77/ia a still more marked rise in 
June, were noticeable. 
(d.) Highest and lowest scores in each month.—The 
highest for April was 5 p.c. of the annual increase in Cyézsus; 
May, 15°5 in Quercus; June, 46°5 in Ttlza; July, 40 in Quercus; 
August, 21 in Quercus; September, 7 in Carpinus. The lowest 
for April was 1 in Zela; May, 9°5 in Pyrus; June, 17°5 in 
Quercus; July, 28°5 in Cytésus and Trlza; August, 8 in 77a; 
September, 1 in Alnus. 
3. Spectes in which only one young tree has been under observation. 
As we have no means of checking the results in these species 
* October 1899. I find that it has done so in this the first available year since trans- 
plantation, the increase having been 35 in the first half-season, and °7o in 
