Ouar. XVIIL 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. 
