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Show 452 CONCLUSION. CHAP. XVIII. examined, but none could be found. What are we to infer from thes.e facts ? Did the three species just named, like their close allies, the several species of Utricularia, aboriginally possess bladders on their rhizo1nes, which they afterwards lost, acquiring in their place u triculiferous leaves ? In support of this view it may be urged that the bladders of Genlisea filijormis 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 1nany species of U tricularia and of two closely allied genera, inhabiting the most distant parts of the worldEurope, ~1\._frica, India, the Malay Archipelago, Australia, North and South A.merica-are admirably adapted for capturing by two 1nethods small aquatic or terrestrial animals, and that they absorb the products of their decay. Ordinary plants of the higher classes procure the rBquisite 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 Droseracere, 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 tho rain. It has also been shown that some other plants can absorb ammonia by CHAP. XVIII. CONCLU ION. 453 their glandular hairs. and th . brought to them by the rain ;~ ~ll.l profit by that of plants which as h . . re IS a second cla s but absorb th ' , d we ave JUSt sec n, cannot d1' ge -t, which the e pr.o ucts of the ~ecay of the animal allies . aid c~~ture~hnamely, U tncularia and its clo e M ll' 'h rom e excellent observations of D, d e lC amp and Dr. Canby, there can scarcel b I. oub.t that Sarracenia a n d D ar· 1I· ngtoni.a may b y d e1 a1 to this class ' though the f·a c t can hardly b e ·a d c e as yet fully proved Th'"' , . . e consi ered h . h . ere Is a thud class of l t w IC feed · p an s products of t~e 1~ now fenerally admitted, on the th b . ' ecay o vegetable matter such e ud s-nest orchis (N tt' ) & ' as th eo Ia ' c. Lastly th · · e well-known fourth class of . t ( ' ere Is mistletoe) h' h . . parasi es such as the ' w Ic are no unshed b th · · living plants. Most ' h owever.' of t h e yp lantes bJeUl ices · of to these four classes obtain part f th . b ong~ng d . . o eu car on hl~ or Inary species, from the at h . ' "-e diversified ;means £ mosp ere. Such are the . ' as ar as at present know b h. higher plants gain their subsistence. n, y w 1Ch INDEX. |
