280 MB. C. DABWIN ON THE ACTION OF 
aleohol they are subjeeted to the iodine solution, they soon almost 
disappear; but this, again, does not invariably occur. Acetic 
acid always caused their rapid disappearance, and without any 
apparent effervescence, a slight granular residue being sometimes 
left; and this occurred with leaves which had been kept so long 
in the solution that they were dead. The acid dissolved, of 
course with effervescence, the crystalline balls of carbonate of 
lime which occupy many of the palisade-cells. When sulphuric 
ether was added, the smaller spheres of transparent matter dis- 
appeared in the course of a few minutes, while the larger ones 
became brownish and granular in their centres ; but this granular 
matter disappeared after a time, empty transparent bag-like 
membranes being left. "Traces of similar membranous envelopes 
eould sometimes be detected after the administration of acetic 
acid. Caustie potash did not act quickly on the spheres, but some- 
times caused them to swellup. I do not know what ought to be 
inferred from the action of these several reagents with respect to 
the nature of the spheres and aggregated masses in which Inever 
saw any movement. 
On two or three occasions the palisade-cells of leaves which 
had been immersed in the solutions, instead of containing large 
transparent spheres, were gorged with innumerable, often 
irregularly-shaped, more or less confluent globules, many of 
them being much smaller than the chlorophyll-grains. This oc- 
curred with a leaf which had been immersed for only 18$ hours 
in a solution of 4 to 1000. After sections of this leaf had been 
cleared with alcohol, it was irrigated with the solution of iodine, 
and the globules rapidly ran together or became confluent, 
forming irregular amorphous masses. 
It was difficult to ascertain whether the chlorophyll-grains 
ever or often became blended with other matter, and thus aided 
in the formation of the transparent spheres. The difficulty was 
partly due to the grains being easily acted on by water. Thus, 
in some sections made and placed in water, and then cleared in 
alcohol, no grains could be distinguished ; while they were distinct 
in sections of the same leaf which had not been wetted before 
being placed in aleohol. Many grains were also found in a dis- 
integrated condition in uninjured leaves which had been kept 
for 47 hours in water. It may be here added that nota single 
sphere could be seen in these leaves; nor were they present in 
leaves slightly injured by being kept for 24 hours ina very weak 
