Cuar. XV.] DROSOPHYLLUM LUSITANICUM. 269 
CHAPTER XV. 
DROSOPHYLLUM—RORIDULA—-BYBLIS—GLANDULAR HAIRS OF OTHER 
PLANTS—CONCLUDING REMARKS ON THE DROSERACEÆ. 
Drosophyllum—Structure of leaves—Nature of the secretion—Manner of 
catching insects—Power of absorption—Digestion of animal substances— 
Summary on Drosophyllum—Roridula—Byblis—Glandular hairs of other 
plants, their power of absorption—Saxifraga—Primula— Pelargonium — 
Erica—Mirabilis—Nicotiana—Summary on glandular hairs—Concludine 
remarks on the Droseracez. 
DrosopHYLLUM LusiTaNnicuM.—This rare plant has been found! 
only in Portugal, and, as I hear from Dr. Hooker, in Morocco. 
I obtained living specimens through the great kindness of 
Mr. W. C. Tait, and afterwards from Mr. G. Maw and Dr. 
Moore. Mr. Tait informs me that it grows plentifully on 
the sides of dry hills near Oporto, and that vast numbers of 
flies adhere to the leaves. This latter fact is well known to 
the villagers, who call the plant the “ fly-catcher,” and hang 
it up in their cottages for this purpose. A plant in my hot- 
house caught so many insects during the early part of April, 
although the weather was cold and insects scarce, that it 
must have been in some manner strongly attractive to them. 
On four leaves of a young and small plant, 8, 10, 14, and 16 
minute insects, chiefly Diptera, were found in the autumn 
adhering to them. I neglected to examine the roots, but I 
hear from Dr. Hooker that they are very small, as in the case 
of the previously mentioned members of the same family of 
the Droseraceie. 
The leaves arise from an almost woody axis; they are 
linear, much attenuated towards their tips, and several inches 
in length. The upper surface is concave, the lower convex, 
with a narrow channel down the middle. Both surfaces, 
with the exception of the channel, are covered with glands, 
supported on pedicels and arranged in irregular longitudinal 
rows. These organs I shall call tentacles, from their close 
resemblance to those of Drosera, though they have no power 
of movement, Those on the same leaf differ much in length. 
