280 GLANDULAR HAIRS: [Cuar. XV. 
146 of water (or 3 grs. to 1 oz.), and the glands were discoloured in 
exactly the same manner as by the infusion of raw meat. 
Another flower-stem was immersed, as before, in a solution of one 
part carbonate of ammonia to 109 of water. The glands, after 1 hr. 
30 m., were not discoloured, but after 3 hrs. 45 m. most of them had 
become dull purple, some of them blackish-green, a few being still 
unaffected. The little masses of protoplasm within the cells were 
seen in movement. The cells of the pedicels were unaltered. ‘The 
experiment was repeated, and a fresh flower-stem was left for 23 hrs. 
in the solution, and now a great effect was produced; all the glands 
were much blackened, and the previously transparent fluid in the cells 
of the pedicels, even down to their bases, contained spherical masses of 
granular matter. By comparing many different hairs, it was evident 
that the glands first absorb the carbonate, and that the effect thus 
produced travels down the hairs from cell to cell, The first change 
which could be observed is a cloudy appearance in the fluid, due to 
the formation of very fine granules, which afterwards aggregate into 
larger masses. Altogether, m the darkening of the glands, and in the 
process of aggregation travelling down the cells of the pedicels, there is 
the closest resemblance to what takes place when a tentacle of Drosera 
is immersed in a weak solution of the same salt. ‘The glands, however, 
absorb very much more slowly than those of Drosera. Besides the 
glandular hairs, there are star-shaped organs which do not appear to 
secrete, and which were not in the least affected by the above 
solutions. 
Although in the case of uninjured flower-stems and leaves the 
carbonate seems to be absorbed only by the glands, yet it enters a cut 
surface much more quickly than a gland. Strips of the rind of a 
flower-stem were torn off, and the cells of the pedicels were seen to 
contain only colourless transparent fluid ; those of the glands including 
as usual some granular matter. These strips were then immersed in 
the same solution as before (one part of the carbonate to 109 of water), 
and in a few minutes granular matter appeared in the lower cells of all 
the pedicels. The action invariably commenced (for I tried the ex- 
periment repeatedly) in the lowest cells, and therefore close to the torn 
surface, and then gradually travelled up the hairs until it reached the 
glands, in a reversed direction to what occurs in uninjured specimens. 
The glands then became discoloured, and the previously contained 
granular matter was aggregated into larger masses. Two short bits of 
a flower-stem were also left for 2 hrs. 40 m. ina weaker solution of one 
part of the carbonate of 218 of water; and in both specimens the 
pedicels of the hairs near the cut ends now contained much granular 
matter; and the glands were completely discoloured. 
Lastly, bits of meat were placed on some glands; these were 
examined after 23 hrs., as were others, which had apparently not long 
before caught minute flies; but they did not present any difference 
from the glands of other hairs. Perhaps there may not have been 
time enough for absorption. I think so, as some glands, on which 
