854 MB. 8. LE M. MOORE'S STUDIES 
eblorophyll bodies can be seen after some time to undergo the 
remarkable changes in form described by Prillieux. Figs. 7 a-e 
and 8 a-g (drawn most of them after two and a half hours’ insola- 
tion) will give a fairly good idea of this. In its simplest form 
the chlorophyll body is faleate or horseshoe-shaped, with the 
wider are closely applied against a side of the cell—its position of 
epistrophe has been changed into one of apostrophe. If the 
various parts of the chlorophyll body can mutually adapt them- 
selves, the forms just described are, so far as my experience goes, 
never departed from even after several hours’ sunlight; but it 
frequently happens that contrary tendencies set in, as is shown 
by one part of the body moving towards one side-wall, while 
another or others make for another side or other sides of the cell. 
The consequence of this centrifugality is the assumption of very 
irregular forms, such as the hatchet and dumbbell, the narrow 
parts connecting the main masses indicating the places where, if 
insolation be continued long enough, the next phase, viz. actual 
division, will take place. To this end the chlorophyll ceases to 
be continuous at some part of the isthmus, and the area of 
separation increasing by the recession of its sundered portions, 
one sees two masses united by a bridge of colourless plasma, 
which is either of uniform width (figs. 8 b, d, and f) or much 
broader in one part than in another (figs. 8 c and e). This 
plasma-bridge lengthens until the side-wall is reached, but some- 
times the cleavage-masses are quite isolated from each other 
(figs. 8 fand g). Occasionally simple contraction and rounding 
occurs (fig. 7 d). The nucleus is frequently brought into view 
by the fragmentation (figs. 8 a, d, e) ; but in some cases it is 
difficult at first sight to distinguish between nucleus and plasma- 
bridge (figs. 8 c, 10 e & h). 
Apostrophe and fragmentation are induced much more rapidly 
in the proximal than in the distal half of the leaf; but as regards 
time, there is some difference between leaves. Thus it is some- 
times possible to trace the effect of the sun five-sixths of the way 
up the leaf after two and a half hours, whereas one may find 
leaves of which the distal cells show no sign of insolation after 
four hours. I have seen fragmentation in the proximal half only, 
and in no case have the whole of the chlorophyll bodies been 
fragmented or apostrophized; whatever the length of exposure 
to the sun, in at least a few of the apical cells no symptom of its 
action " a itself. 
