248 MR. C. DARWIN ON THE ACTION OF CARBONATE 
` degree with aggregated masses; and here root-hairs arose from 
cells including a very few minute spheres. 
In longitudinal sections of the above roots, the cells in the 
parenchyma at different depths from the surface were seen to 
include spheres, but many of them were of small size and pale- 
coloured. There was no marked increase in the amount of 
aggregated matter in the cells closely surrounding the vascular 
bundle, as is so often the case with other plants. 
The third cut-off root was placed under the microscope, and 
was irrigated with a solution of 7 to 1000. After 13 minutes very 
small translucent granules could be seen in many of the cells; 
and after 35 minutes several cells near the cut-off end contained 
moderately large spheres of translucent matter. But I suppose 
that the solution was too strong; for the granules disappeared 
after about 45 minutes, except close to the tip; and the higher 
parts of the root no longer presented a striped appearance. 
Nevertheless the large spherical, oval, and oddly shaped masses 
in the cells near the cut-off end remained perfect, and they were 
watched for the next 21 hours. During this time they slowly 
changed their shapes, but not afterwards, though observed for 
nearly 24 hours. For instance, two spheres in one cell became 
confluent and formed an oval mass; two other spheres ran 
together and formed a dumbbell-shaped body, which ultimately 
changed into a sphere; and, lastly, an irregular mass first became 
oval, then united itself with another oval mass, and both together 
became spherical. 
Saxifraga umbrosa.—This plant, from its affinity to the Drose- 
races, was cursorily observed. Many of the exterior cells of 
roots which had been immersed for 19 hours in a solution of 
4 to 1000 were filled with brown granular matter. Only two or 
three cells in a longitudinal row were thus filled; but sometimes 
four or five such short rows were grouped together; and these 
groups alternated with rows of colourless cells. 
Sarracenia purpurea.—Tlwo rootlets were left in water for 
24 hours, but they presented no granules or aggregated masses. 
They were then irrigated with a solution of 7 to 1000, and in 
20 minutes pale-brown aggregated masses could be distinctly 
seen near their tips. Two other, almost colourless, rootlets were 
left for 1 hour 10 minutes in the same solution ; and now all the 
exterior cells contained brown granular matter, but much darker 
in some cells than in others. Some of the cells contained, 
