CHAP. XVIU. CONCLUSION. 453 



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. 



