leaf serving for very different purposes one part for true digestion,
and another for the absorption of decayed animal matter. We can thus
also understand how, by the gradual loss of either power, a plant might
be gradually adapted for the one function to the exclusion of the
other; and it will hereafter be shown that two genera, namely
Pinguicula and Utricularia, belonging to the same family, have been
adapted for these two different functions. [page 332]
CHAPTER XV.
DROSOPHYLLUM RORIDULA BYBLIS GLANDULAR HAIRS OF OTHER PLANTS CONCLUDING
REMARKS ON THE DROSERACE .
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 Concluding remarks on the Droseraceae.
Drosophyllum lusitanicum. 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 Droseraceae.
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