78 4 
The Action of Light on Plants . [December, 
The substructures and architectural arrangements for the 
Eastern arc of the Dial were made subservient to many 
purposes, chief of which we noticed a narrow gallery or 
chasm running due N. and S. I hardly know how to 
describe it. In ground plan it would be a narrow parallelo- 
gram, about 6 feet wide ; in side elevation, wedge-shaped — 
its central line in the direction of the mean angular midday 
elevation of the sun ; the vertical height of this wedge being 
that of the arc, or about 60 feet. The apex of this wedge 
is a well-cut horizontal slit, about 2 inches wide, in a finely- 
dressed stone, and not to be noticed at first in the ruined 
condition of the outside ; but inside the curious vault at 
midday its meaning is evident, as the line of sunlight falls 
across an arc, ready marked, recording the sun’s vertical 
height at noon during the year. 
The visit was an interesting one, but I left the “ Junter 
Munter ” with the idea that it was only the scientific toy of 
a rich man, with yearnings maybe ahead of his time ; and 
when “Jey Sing” was gathered to his fathers, I imagine 
the “ Junter Munter” soon fell into a respectable disuse. 
II. THE ACTION OF LIGHT ON PLANTS. 
Oil 
S LN his Presidential Address at the Sheffield Meeting of 
L the British Association, Dr. Allman remarked that 
in by farj the greater number of plants the proto- 
plasm of most of the cells which are exposed to the sun- 
light undergoes a curious and important differentiation, 
part of it becoming separated from the remainder in the 
form usually of green granules, known as chlorophyll gra- 
nules. To the presence of chlorophyll is due one of the 
most striking aspects of external nature — the green colour 
of the vegetation which clothes the surface of the earth ; 
and with its formation is introduced a function of funda- 
mental importance in the economy of plants, for it is on the 
cells which contain this substance that devolves the faculty 
of decomposing carbonic acid. On this depends the assi* 
