452 CONCLUSION. CHAP. XVIIL 



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, Austra- 

 lia, North and South America are admirably adapted 

 for capturing by two methods small aquatic or terres- 

 trial 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 

 Droseraceae, 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 sub- 

 stances, such as pollen, seeds, and bits of leaves. No 

 doubt their glands likewise absorb the salts of am- 

 monia brought to them by the rain. It has also been 

 shown that some other plants can absorb ammonia by 



