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Show 162 DROSERA ROTUNDIFOLIA. CHAP, VII. eight closely inflected. The leaf remained in this state for two da~:) After 2 hrs. 20m. only fifty-nine ~entacles inflect?d; but after 5 hrs. all the tentacles closely In.flected exceptmg t~o which were not affected, and eleven w~uch were only sub-mflected; after 7 hrs. blade considerably Inflected; after 12 hrs. much re-expansion. . (5) After 4 hrs. all the tentacles but fourteen Inflected; after 9 hrs. 30m. beginning tore-expand. . (6) After 1 hr. thirty· six tentacles In~ected; after 5 hr~. all but fifty-four inflected; after 1~ hrs. considerable re-~xpans10n. (7) After 4 hrs. 30m. only thirty-fi:e te~tacles In~ccted or sub-inflected, and this small amount of Infl~ctiOn never Incr·eased. Now for the seven corresponding leaves I~ water:- (1) After 4 hrs. thirty-ei.ght te~tacles Inflected; but aftor 7 hrs. these, with the exceptiOn of s1x, re-expanded . . (2) After 4 hrs. 20 m. twenty inflected ; these after 9 hrs. partially re-expanded. . (3) After 4 hrs. five inflected, whiCh began to re-expancl after 7 hrs. ( 4) After 24 hrs. one inflected. (5), (6) aud (7) Not at all affected, though observed .for 24 lus., exeopting the short tentacles on the borders of the disc, which as usual formed a ring. A comparison of the leaves ill: the. solution,. especially of the first five or even six on the hst, with those In the water, after 1 hr. or after 4 hrs., and in a still more marked degree after 7 hrs. or 8 hrs., could not leave the least doubt that the solution had produced a great effect. This was shown not only by the vastly greater number of inflected tentacles, b~t b_Y the degree or closeness of their inflection, and by that of their blades. Yet each gland on leaf No.1 (which bore 255 glands, all of which, excepting five, were inflected in 30m.) could not have received more than one-four-millionth of a grain ('0000162 mg.) of the salt. Again, each gland ~n leaf No: 3 (whi~h bore 233 glands, all of which, except nine, were Inflected m. 2 hrs. 30m.) could have received at most only the 3onhoo of a grain, or ·ooooun mg. Four leaves were immersed as before in a solution of one part to 656,250 of water (1 gr. to 1500 oz.) ; but on this oc?~sion I happened to select leaves which were very little sensttiv~, .as on other occu::;ions I chanced to select unusually sensitive leaves. The leaves were not more affected after 12 hrs. than CHAP. VII. PHOSPHATE OF AMMONIA. 163 the four corresponding ones in wate:; but after 24 hrs. they were slightly more inflected. Such evidence, however, is not at all trustworthy. Twelve leaves were immersed, each in thirty minims of a solu~ on of one pa~t to 1,~12,500 of ':ate.r (1 gr. to 3000 oz.); so that eac~ leaf received 480 ~0. of a ~rain ( 00135 mg.). The leaves were not In very good conditiOn ; four of them were too old and of a dark red c~lour; four were too pale, yet one of these latter acted well ; the four others, as far as could be told by the eye seemed in excellent condition. The result was as follows:- ' (1) ~his was a pale leaf; after 40 m. about thirty-eight tentacles Inflected; after 3 hrs. 30 m. the blade and many of th outer tentacles . inflected; after 10 hrs. 15 m. all the tentacle: but seventeen Inflected, and the blade quite doubled up· afte . 24 hrs. all the tentacles but ten more or less inflected. ' Mos~ ?f them were closely inflected, but twenty-five were only subInflected. (2) After 1 hr. 40 m. twenty-five tentacles inflected; after 6 hrs. all bu~ twenty-one inflected; after 10 hrs. all but sixteen more or less Inflected ; after 24 hrs. re-expanded. (3) After 1 hr. 40 m. thirty-five inflected· after 6 hrs "a large number" (to quote my own memor~ndum) infle~ted, but from want of time they were not counted; after 24 hrs. reexpanded. ( 4) After 1 hr. 40 m. about thirty inflected ; after 6 hrs. u a large number all round the leaf n inflected, but they were not counted; after 10 hrs. began to re-expand. (~)to (12) These 'were not more inflected than leaves often are In ~ater, having respectively 16, 8, 10, 8, 4, 9, 14, and 0 tentacles In~ected. Two of these leaves, however, were remarkable from.havmg their blades slightly inflected after 6 hrs. With respect to the h~elve corresponding leaves in water, (1) had, after 1 hr. 35 m., fifty tentacles inflected, but after 11 hrs. only twent~-two. rem~ined so, and these formed a group, with the blade at t~Is pmnt slightly inflected. It appeared as if this leaf had .been In so:me manner accidentally excited, for instance by a particle of ammal matter which was dissolved by the water. (2) After 1 hr. 45 m. thirty-two tentacles inflected, but after 5 hrs. 30 m. only twenty-five inflected, and these after 10 brs. all re-expanded; (3) after 1 hr. twenty-five inflected which afte: 10 hrs: 20 m. were all re-expanded ; ( 4) and (B) after 1 .hi. 35m. SIX and seven tentacles inflected, which re ·expanded after 11 hrs.; (6), (7) and (8) from one to three inflected, which M 2 |
