100 CHRISTISON—OBSERVATIONS ON 
The correspondence between the single tree of the recent 
period and the three earlier ones is even more marked than in 
the last species (Horse Chestnut). Indeed, it is almost precise in 
every particular, with the trifling exception that the increase is 
more equally diffused over August and September in No. 16 
than in the others. There is an appreciable though not excessive 
preponderance of the first half-season, due to the unusually large 
proportion of 42 per cent. of the increase being in June. 72 per 
cent. of the increase takes place in the two months June and 
July. The Sycamore is the first among forest trees to be in full 
foliage in the Edinburgh district, yet the girth-increase is slow to 
start, and is slight in May. It makes amends, however, by 
rushing on quickly in June. The best single records per month 
are 5 in April, 35 in May, 60 in June, 50 in July, 35 in August, 
and 5 in September. 
No. 12.—ACER CAMPESTRIS. 
| Girth in 
Year, Apr. | May. |June.| July. | Aug. | Sept. et on = me eae . 
; ‘ Observation. 
1892, 5 20 35 55 45 5 60 105 
1893. 10 20 30 85 30 5 60 70 
1894 5 10 40 35 10 5 55 50 
1895 20 10 5 20 15 
1896. 15 30 40 15 45 55 
1897, 10 25 25 30 35 55 
Total, | 20 75. | 180 | 200 | 185 15 275 350 
bog De 12 geet on OT 28 44 56 19 
The conduct of No. 12 has been most erratic. Starting 
1892 with the very large increase of 1°65, of which sieee Hike 
were due to the last half-season, it fell off, in that half only, the 
next two years, till in the third the first half was slightly in excess. 
In the fourth year the foliage looked very sickly and some twigs 
