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Show 3B8 DROBOPHYLLUM LUSITANICUM. CHAP. XV. pe< l1. ce 1s and to the minute. sessiled ohn es. , B. ·e fo. re a l l h b en in any way stimulate , t e ex tenor cells g anc as e . . fl 'd h oommool y Contain only hm p1d pu. rple u1 ; t . e more cen t ral ones l·ncluding mulberrJv -hke• masse• s of purp. le granul arm atter· A leaf was place.d 1n a httlfe solutwn of one par· t of carbonate of ammonia . to 146 o water (3 gr. s . t o 1 oz . ) , and the glands .w ere Instantly darkened ~ h b . . d a. nd ver.y soon became black , th1s c ange e1ng ue -';f- • f h . to the strongly marked aggregation o t eu cou~onts, more especially of the inner cells. Another ~oaf was placed in a solution of the same str.ength of n1trato ?f ammonia, and the glands were shghtly darkened m 25m., more so in 50 1n., and after 1 hr. 30 m. were of so dark a red as to appear almost black. Other loaves were placed in a weak infusion of raw moat and in human saliva, an d the g l and s we re much darkened in 25 m. and after 40 m. were so dark as ahnost to deser;e to be called black. Even immersion for a whole day in distilled water occasionally induces some aagregation within the glands, so that they become of a 0 darker tint. In all these cases the glands are affected in exactly the sa1ne manner as tho~e of Drosera. Milk, however, which acts so energetically on Drosera seems rather less ffoctive on Drosophyllum f~r the glands · were only slightly darkened by an i~mersi~n of 1 hr. 20 m., ~ut became docidedl~ darker after 3 hrs. Leaves wh1ch hau been left fOI 7 hrs. in an infusion of raw meat or in sali v~ were placed in the solution of carbo~ate of ammon~~' and the glands now became green1sh ; w horeas, 1f they had been first placed in the carbonate, they wou~d have become black. In this latter case, the amm~ma probably combines with the acid of th~ secretw;: and therefore does not act on the colounng matte. ' but when the glands are first subjected to an orgamc CHAP. XV. DIGESTION. 339 fluid, either the acid is consumed in the work of digestion or the cell-walls are rendered more permeable, so that the undecomposed carbonate enters and acts on the colouring matter. If a particle of the dry carbonate ·is placed on a gland, the purple colour is quickly discharged, owing probably to an excess of the salt. The gland, moreover, is killed. Turning now to the action of organic substances, the glands on which bits of raw n1eat were placed became dark-coloured ; and in 18 hrs. their contents were conspicuously aggregated. Several glands with bits of .alLu1nen and fibrin were darkened in between 2 hrs. and 3 hrs. ; but in one case thn purple colour was completely dis~harged. Some glands which had caught flies were compared with others close by; and though they did not differ much in colour, there was a n1arked difference in their state of aggregation. In so1ne few instances, however, there was no such difference, and this appeared to be due to the insects having been caught long ago, so that the glands had recovered their pristine state. In one case, a group of the sessile colourless glands, to which a small fly adhered, presented a peculiar appearance; for they had become purple, owing to purple granular Inatter coating the cell-walls. I may here mention as a caution that, soon after some of my plants arrived in the spring from Portugal, the glands were not plainly acted on by bits of meat, or insects, or a solution of amwonia-a circumstance for which I cannot account. . Digestion of Solid Animal Matter. - Whilst I was trying to place on two of the taller glands little cube~ of albumen, these slipped down, and, besmeared with secretion, were left resting on so1ne of the small sessi] e glands. After 24 hrs. one of these cubes was found z 2 |