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Chap. XVIII.

no doubt serve in part as reservoirs for water, but I have not heard of any case, besides the present one, of such organs having been acquired developed solely for this purpose. Prof. Oliver informs me that he knows of only two or three other species of Utricularia are provided with these appendages; and the section group containing them has in consequence received the name of orchidioides. All the other species of Utricularia, and as well as of certain closely related genera, are either aquatic or marsh plants; and therefore, are therefore on the principle of nearly allied plants generally having a similar constitution, a never-failing supply of water would probably be of great importance to our present species. U. montana and We can thus understand the cause reason of the development of its tubers, and of their number on the same plant, amounting in one instance to at least twenty.

Utricularia nelumbifolia, amethystina, griffithii, cærulea, orbiculata, multicaulis.

As I wished to know whether the bladders on the rhizomes of other species of Utricularia, together with & of the species of certain closely allied genera, had the same essential structure as those of U. montana, and likewise captured prey,

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Chap. XVIII.

it was first it had been measured, but in another direction only one-third of its original supposed thickness. The other tuber was a fourth shorter, an eighth less thick in the direction in which it was originally it had been measured, but & only half as thick in another direction.

A slice was cut from one of these shrivelled tubers and examined. The cells still contained much water and no air, but they were more rounded or less angular than before, with & their walls not nearly so straight; it was therefore clear that they had contracted. The tubers, as long as they are remain alive, have a strong attraction for water; the shrivelled one, from which a slice had been cut, was left in water for 22 hrs. 30 m. and its surface became as smooth and tense as it originally was. On the other hand, a shrivelled tuber, which by some accident had been separated from its rhizome, and which appeared to be dead, did not swell in the least, though left for several days in water.

With many kinds of plants, tubers, bulbs &c

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Chap. XVIII

affects of the solution became aggregated sometimes round the nucleus, and sometimes into a separate masses; and that these then often tended to coalesce. The primordial utricle or protoplasm lining the processes was also thickened, here and there, into the most very irregular and diversified specks of yellowish translucent matter, as occurred with those of U. neglecta under similar treatment. I did not observe that these specks apparently change their forms.

The minute transversely elongated two-armed glands on the valve were also affected by the solution; for they now now afterwards contained several, sometimes as many as six or eight, almost spherical masses of translucent matter, tinged with yellow. These masses slowly changed their forms and positions. We may therefore infer that these glands serve for absorption. This fact indicates the use or function of the Whenever a little water is expelled from a bladder containing animal matter, by the means formerly specified, more especially by the generation of bubbles of air, it will fill the cavity in which the valve