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Dionæa. Down. Nov. 1872

The secreting cell glands consist of circular plate, convex on upper surface, formed of 20-30 polygonal cells, with purple contents; supported on extremely short-footstalk — homologues of tentacles of Drosera — They are thickly studded over the leaf, but become rare towards bases of spikes— Besides these glands there are single stomata, & stom wd other bodies which I believe to be stomata with which have the appearance of a flower with its expanded petals. —

Several spiral vessels run into the spikes.

The vascular bundles run up the mid-rib of leaf & send off numerous branches almost at right ∟' on both sides; these often occasionally divide & towards the margin of leaf they often divide & reunite & form a complex inosculation. In some of these inosculations I saw the bundle spiral vessels forming

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Dionæa

double double loops, as figured in Drosera — I saw many curious [sketch] in these vessels by two points in content — Several vessels run up spikes, stopping at different height, one running up to apex. — This fact alone renders it probable that spiral vessels have no relation with secretion or sense of touch. — (The secreting glands on surface of leaf, I feel sure, have no spiral vessels running to them: their structure & contents are exactly like the outer layer of cells of glands in Drosera. —

(Sensitive Filament formed of elongated cells, (homologues of inner cells of glands of Drosera with purple fluid; cells not spirally arranged:— apex consist of 1 or 2, or 3, sometimes separated points pointed cells.

Close to base diameter suddenly decrease there is a collar & the cellular structure changes — probably for bending without injury to filament when leaf shut, with & pressed together with surprising force.

[2v]

[sketch]

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Nov. 2d. 1872

Dionæa Down.

Sensitive filament terminates in single or double point. — a tapering spire.— towards base is contracted & formed of broken cells; beneath which a distinct articulation, (see Back) & the basal part clearly, widens downwards & is again formed of differently shaped polygonal cells. No trace of spiral vessels out of the spiral cells as in Drosera.

In one specimen which had been exposed to alcohol for 24˚ I saw distinctly a very fine central vessel in centre, with pale brown fluid content in parts & in other parts aggregated masses of brown matter, containing very minute hyaline pale brown solid spheres.— The [probably] the nerve. — The sensitive filament rests on ordinary cellular tissue — I have been looking again for this vessel & feel rather doubtful— if there is one, there are more. Can transverse partitions of cells have burst owing to alcohol.— Nothing can be seen without alcohol.— Say I believe — no vessels in fresh specimen can

[3v]

[sketch] single point — much elongated cells —Broader cells — Joint

polygonal cells —stet

be seen running from the Filament down whole uncut leaf after alcohol or before alcohol. —

Frank has been looking & thinks with me that there is a vessel.— As for Drosera we have reason to believe that the motor-influence cannot be sent through cellular tissue alone, there is reason to think that this excessively fine vessel is the channel of Communication.—

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Dionæa Down 1872

The spikes terminate in fine single point: I saw in one spec. an lon elongated spindle-shaped cell, at end of spinal vessel, & of larger diameter than the spiral; (but this did not occur in other specimens, so say nothing about them.—

The petaloid bodies, project from surface— say besides ordinary stomata, say that these exist, & perhaps are modified stomata.

The chief movement is on line of midrib & this is wonderfully extremely prominent on under side. Nitschke says (Bot Zeitung 1860 p. 243.) that it sensitive — (try by Pricking) — (I find by wonder pincers in feeble leaf, that when distal end kept flat open, all power of closing apparently(?) is prevented.)

All movement does not lie in midrib— for whole lamina of leaf curls when opposite side cut away — Placed 3 sensitive tentacles in C. of Ammon. 3 gr to 1 oz. & counted cells very dark & wonderfully segregated. —

[Nitschke, Theodor Rudolf Joseph. 1860. Ueber die Reizbarkeit der Blätter von Drosera rotundifolia L. Botanische Zeitung 18.]