66 
Keeble .- — The Hanging Foliage of 
Branch bearing bright green leaves, Amhersiia nobilis. 
io 
5 
5 
5 
io 
io 
5 
5 
5 
5 
5 5 
6 5 
Time in seconds of ascent ) 0 r r 
often bubbles \ 6 5 53 £8 62 60 
Average time of ascent of 10 bubbles — 59 seconds. 
Branch bearing red hanging foliage, Amherstia nobilis. 
Time in seconds of ascent 
of ten bubbles 
10 
IO 
IO 
IO 
IO 
IO 
IO 
II 
8 
IO 
II 
II 
II 
9 
II 
IO 
IO 
II 
1 1 
1 1 
13 
IO 
12 
9 
9 
12 
IO 
IO 
9 
11 
12 
10 
8 
TO 
10 
9 
9 
IO 
II 
9 
9 
II 
IO 
II 
10 
II 
1 1 
9 
IO 
11 
107 
102 
102 
98 
102 
Average time of ascent of 10 bubbles =102 seconds. 
Now the number of leaflets on the older branch was ten, 
on the younger twenty-four ; and measurement of surface (by 
tracing the outlines of the leaflets on thin paper, cutting out 
these shapes, and weighing), gave the surface of the young 
leaves equal to twice that of the older. Therefore in this 
instance the rates of transpiration of equal surfaces of young 
and old leaves are as 1 : 4 — i.e. the older leaves transpire, 
roughly speaking, four times as rapidly as the younger 
hanging leaves. 
Another example of a similar experiment may be given. 
Three branches of Amherstia nobilis , of course from the 
same tree, were taken. On one, the leaves were thin, young, 
bright red ; on another, older, as evidenced by their brown- 
red colour ; on the third, bright green. 
