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Show 44 DROSERA ROTUNDIFOLIA. CHAP. III. 10 (seconds)· an d I· n 13 s · were conspitc uo1u sly darken in s. · ' ll spherical masses of pro op asm darker. In 1 m .. e~tre~elyh:m:ells of the pedicels close beneath could be seen ansing Jn ~ the cushions on which the longthe glands, as well as In t In several cases the process headed marginal glan~s 1 r~~~ a length twice or thrice as great travelled down the pediC~ s about 10 m. It was interesting to as that of the glands, In t 'ly an·ested at each transverse h ss momen ari t observe t e proce ll d then to see the transparen partition between two c~ ~' 1 a~ almost flashing into a cloudy contents of the cell next 0~ ~he pedicels, the action proceeded mass. In the lo~er par bout 20 m. before the cells halfway dsloowwne r,t hseo ltohnagt Imt atrog~ink a ~ an d submarginal tentacles became aggregated.. h rbonate of ammonia is absorbed ?Y We may Infer that t e ·~:action being so rapid, but from Its the glan~s, not only fr~ff~rent from that of other salts. As t~e effect bemg somewhat I t acid belonging to the acetic d h excited secre e an l . t glan s, w en ' . b bl at once convertec 1n o a series, the ca1~bonate IS pr~ ~l ~resently see that the acetate salt of thi~ senes; and w~ t~o: almost or quite as energetically of ammoma causes aggrega: dro sofa solution of one part of as does the carbonate. If a ewor 1p r to 1 oz.) be added to the the carbon·aat e to 437 of watefr ( g h. ed tentacles or to paper h' b udes rom crus ' purple flui ~ IC ex d 'th them the fluid and the paper are stained by bemg rub be . WI . ' Nevertheless some purple changed into ~ pale dirty ~re~~~ 1 hr. 30m. within the glands colour could st~ll be dete?te ~ twice the above strength (viz. of a leaf left In a soi~tw;4 oh the cells of the pedicels close 2 grs. to 1 oz.) ; and a . er t ~s. d pheres of protoplasm of a beneath the ?lands still ;o~ al~e w ~hat the ammonia had not fine purple tint. These ac s sl o . the colour would have entered as a carbonate, fo~ ot Jerwi~~metimes observed, espebeen discharged. I have, lOwever, ~ ins of very pale cially with the long-beaded tentacles on the lmadrg well as the leaves I· mmerse d I·n a so lution ' th. at the gd a. n sd aisn these cases upper cells of the pedicels were disc~lou~e h ~n been absorbed. I presume that the unchang~d car ona e a a e ating process The appearance above descnbed, of the ggr g t 't'on being arrested for a short t~me at each trans:ers~::~~:rd~ impresses the mind with the Idea of matter passinlt_ the other from cell to cell. But a~ the c.ells o~e benea articles are undergo aggregation when InorganiC and Insolu~l7e!t in these placed on the glands, the process mus\~J ~ m the glands, cases, one of molecular change, transmi e ro CHAP. III. THE PROCESS OF AGGREGATION. 45 independently of the absorption of any matter. So it may possibly be in the case of the caTbonate of ammonia. As, however, the aggTegation caused by this salt havels down the tentacles at a quickeT rate than when insoluble paTticles are placed on the glands, it is probable that ammonia in some form is absorbed not only by the glands, but passes down the tentacles. Having examined a leaf in water, and found the contents of the cells homogeneous, I placed it in a few drops of a solution of one part of the carbonate to 437 of water, and attended to the cells immediately beneath the glands, but did not use a very high power. No aggregation was visible in 3 m.; but after 15 m. small spheres of protoplasm were formed, more especially beneath the long-headed marginal glands; the process, however, in this case took place with unusual slowness. In 25 rn. conspicuous spherical masses were present in the cells of the pedicels for a length about equal to that of the glands; and in 3 hrs. to that of a third or half of the whole tentacle. If tentacles with cells containing only very pale pink fluid, and apparently but little protoplasm, are placed in a few drops of a weak solution of one part of the carbonate to 4375 of water (1 gr. to 10 oz.), and the highly transparent cells beneath the glands are carefully observed under a high power, these may be seen first to become slightly cloudy from the formation of numberless, only just perceptible, granules, which rapidly grow larger either from coalescence or from attracting more protoplasm from the surrounding fluid. On one occasion I chose a singularly pale leaf, and gave it, whilst under the microscope, a single drop of a stronger solution of one part to 437 of water; in this case the contents of the cells did not become cloudy, but after 10 m. minute irregular granules of protoplasm could be detected, which soon increased into irregular masses and globules of a greenish or very pale purple tint; but these never formed perfect spheres, though incessantly changing their shapes and positions. With moderately red leaves the first effect of a solution of the carbonate generally is the formation of two or three, or of several, extremely minute purple spheres which rapidly increase in size. To give an idea of the rate at which such spheres increase in size, I may mention that a rather pale purple leaf placed under a slip of glass was given a drop of a solution of one part to 292 of water, and in 13m. a few minute spheres of protoplasm were formed ; one of these, after 2 hrs. 00 m., was about two-thirds of the diameter of the cell. After 4 hrs. 25 m. |