Chap. XV.] THEIR POWER OF ABSORPTION. 281 



aggregated. The continually changing forms of the little masses 

 of protoplasm are not due to the absorption of water, as they were 

 seen in glands kept dry. 



A flower-stem, still attached to a i)lant, was bent (May 29) so 

 as to remain immersed for 23 hrs. 30 m. in a strong infusion of raw 

 meat. The colour of the contents of the glands was slightly 

 changed, being now of a duller and more purj)le tint than before. 

 The contents also appeared more aggregated, for the spaces between 

 the little masses of protoplasm were wider; but this latter result 

 did not follow in some other and similar experiments. The masses 

 seemed to change their forms more rapidly than did those in wrter; 

 so that the cells had a ditterent appearance every four or five min- 

 utes. Elongated masses became in the course of one or tw3 

 minutes spherical; and spherical ones drew themselves out and 

 united with others. Minute masses rapidly increased in size, and 

 three distinct ones were seen to unite. The movements were, in 

 short, exactly like those described in the case of Urosera. The 

 cells of the pedicels were not allected by the infusion; nor were 

 they in the following experiment. 



Another flower-stem was placed in the same manner and for the 

 same length of time in a solution of one part of nitrate of ammonia 

 to 146 of water (or 3 grs. to 1 oz.), and the glands were discol- 

 oured 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 diflfer- 

 ent hairs, it was evident Ihat the glands first absorb the carbon- 

 ate, and that the eflTect 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, in the 

 darkening of the glands, and in the process of aggregation travel- 

 ling down the cells of the pedicels, there is the closest resemblance 

 to what takes place when a tentacle of Drosera is immersed in n 

 weak solution of the same salt. The glands, however, absorb very 

 much more slowjy 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 



