In order to test this view, I divided transversely with the point of a lancet the central trunks of four leaves, just beneath the main bifurcation; and two days afterwards placed rather large bits of raw meat [page 249] (a most powerful stimulant) near the centre of the disc above the incision—­that is, a little towards the apex—­with the following results:—­

[(1) This leaf proved rather torpid:  after 4 hrs. 40 m. (in all cases reckoning from the time when the meat was given) the tentacles at the distal end were a little inflected, but nowhere else; they remained so for three days, and re-expanded on the fourth day.  The leaf was then dissected, and the trunk, as well as the two sublateral branches, were found divided.

(2) After 4 hrs. 30 m. many of the tentacles at the distal end were well inflected.  Next day the blade and all the tentacles at this end were strongly inflected, and were separated by a distinct transverse line from the basal half of the leaf, which was not in the least affected.  On the third day, however, some of the short tentacles on the disc near the base were very slightly inflected.  The incision was found on dissection to extend across the leaf as in the last case.

(3) After 4 hrs. 30 m. strong inflection of the tentacles at the distal end, which during the next two days never extended in the least to the basal end.  The incision as before.

(4) This leaf was not observed until 15 hrs. had elapsed, and then all the tentacles, except the extreme marginal ones, were found equally well inflected all round the leaf.  On careful examination the spiral vessels of the central trunk were certainly divided; but the incision on one side had not passed through the fibrous tissue surrounding these vessels, though it had passed through the tissue on the other side.*]

The appearance presented by the leaves (2) and (3) was very curious, and might be aptly compared with that of a man with his backbone broken and lower extremities paralysed.  Excepting that the line between the two halves was here transverse instead of longitudinal, these leaves were in the same state as some of those in the former experiments, with bits of meat placed on one side of the disc.  The case of leaf (4)

* M. Ziegler made similar experiments by cutting the spiral vessels of Drosera intermedia(’Comptes rendus,’ 1874, p. 1417), but arrived at conclusions widely different from mine. [page 250]

proves that the spiral vessels of the central trunk may be divided, and yet the motor impulse be transmitted from the distal to the basal end; and this led me at first to suppose that the motor force was sent through the closely surrounding fibrous tissue; and that if one half of this tissue was left undivided, it sufficed for complete transmission.  But opposed to this conclusion is the fact that no vessels pass directly from one side of the leaf to the other, and yet, as we have seen, if a rather large bit of meat