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examined, but none could be found. What are we to infer from these facts? Did the three species just named, like their close allies, the several species of Utricularia, aboriginally possess bladders on their rhizomes, which they afterwards lost, acquiring in their place utriculiferous leaves? In support of this view it may be urged that the bladders of Genlisea filiformis appear from their small size and from the fewness of their quadrifid processes to be tending towards abortion; but why has not this species acquired utriculiferous leaves, like its congeners?

CONCLUSION.-It has now been shown that many species of Utricularia and of two closely allied genera, inhabiting the most distant parts of the world— Europe, Africa, India, the Malay Archipelago, Australia, North and South America-are admirably adapted for capturing by two methods small aquatic or terrestrial animals, and that they absorb the products of their decay.

Ordinary plants of the higher classes procure the requisite inorganic elements from the soil by means of their roots, and absorb carbonic acid from the atmosphere by means of their leaves and stems. But we have seen in a previous part of this work that there is a class of plants which digest and afterwards absorb animal matter, namely, all the Droseraceæ, Pinguicula, and, as discovered by Dr. Hooker, Nepenthes, and to this class other species will almost certainly soon be added. These plants can dissolve matter out of certain vegetable substances, such as pollen, seeds, and bits of leaves. No doubt their glands likewise absorb the salts of ammonia brought to them by the rain. It has also been shown that some other plants can absorb ammonia by

their glandular hairs; and these will profit by that brought to them by the rain. There is a second class of plants which, as we have just seen, cannot digest, but absorb the products of the decay of the animals which they capture, namely, Utricularia and its close allies; and from the excellent observations of Dr. Mellichamp and Dr. Canby, there can scarcely be a doubt that Sarracenia and Darlingtonia may be added to this class, though the fact can hardly be considered as yet fully proved. There is a third class of plants which feed, as is now generally admitted, on the products of the decay of vegetable matter, such as the bird's-nest orchis (Neottia), &c. Lastly, there is the well-known fourth class of parasites (such as the mistletoe), which are nourished by the juices of living plants. Most, however, of the plants belonging to these four classes obtain part of their carbon, like ordinary species, from the atmosphere. Such are the diversified means, as far as at present known, by which higher plants gain their subsistence.

INDEX.

ABSORPTION.

A.

ABSORPTION by Dionæa, 295
by Drosera, 17

421

by Drosophyllum, 337
by Pinguicula, 381
by glandular hairs, 344

by glands of Utricularia, 416,

by quadrifids of Utricularia,
413, 421

by Utricularia montana, 437
Acid, nature of, in digestive secre-
tion of Drosera, 88

present in digestive fluid of
various species of Drosera, Dio-
næa, Drosophyllum, and Pingui-
cula, 278, 301, 339, 381
Acids, various, action of, on Drosera,
188

of the acetic series replacing
hydrochloric in digestion, 89

arsenious and chromic, action
on Drosera, 185

-, diluted, inducing negative
osmose, 197

Adder's poison, action on Drosera,
206

Aggregation of protoplasm in Dro-
sera, 38

in Drosera induced by salts of
ammonia, 43

caused by small doses of
carbonate of ammonia, 145
of protoplasm in Drosera, a
reflex action, 242

in various species of

Drosera, 278

in Dionæa, 290, 300

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Barium, salts of, action on Drosera,
183

Bases of salts, preponderant action
of, on Drosera, 186

Basis, fibrous, of bone, its digestion
by Drosera, 108
Belladonna, extract of, action on
Drosera, 84

Bennett, Mr. A. W., on Drose a, 2
coats of pollen-grains not
digested by insects, 117
Binz, on action of quinine on white
blood-corpuscles, 201

on poisonous action of quinine
on low organisms, 202
Bone, its digestion by Drosera, 105
Brunton, Lauder, on digestion of
gelatine, 111

on the composition of casein,
115

on the digestion of urea, 124
of chlorophyll, 126
of pepsin, 124

By blis, 343

C.

Cabbage, decoction of, action on
Drosera, 83

Cadmium chloride, action on Dro-
sera, 183

Cæsium, chloride of action on
Drosera, 181

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