22 
29th (dull days) the leaves on a number of plants performed similar 
movements, reaching almost identical highest and lowest limits each day. 
On the 30th (bright) the movement in the morning hours was con- 
tinued down much further than on the preceding days; the tips of the 
leaves being as much as + in. lower than at the same time on the 
previous day. Likewise on the 31st (also a bright morning) the lowest 
readings were (as on the 30th) considerably below the average. 
November Ist was a dull morning clearing later. The downward 
movement stimulated by the stronger light, since on fine a 
mornings alike the lowest point attained is reached approximately at the 
e hour. In other words, on a bright morning the movement down- 
wards is not continued to a later hour but is more rapid, and continuing 
over the same time necessarily lower. 
At night the extreme highest point is reached before midnight. 
Slight variations were noticed in the height attained on successive 
nights by individual leaves. I consider temperature to be at any rate 
one important factor affecting the movement 
The heating arrangements of one of the conservatories in which 
some ofthe plants were placed were such that whilst on some nights 
temperature would be as high as 27° to 30? C., on others it would 
| 1 making an 
angle of 45? with : m, were often found to have risen in the Mine 
a wee such an extent that they pointed i 
angle of 135? with the stem immedi dg "their à et ree, i 
