the pollen itself, these movements being apparently dependent on 
contraction of the protoplasm, or on varying hygrometie conditions. 
Hence, then, so far as feeling goes, if we admit sensitiveness as the 
equivalent of sensation, we cannot deny that a plant possesses the 
same faculty as an animal. If we take locomotion, or the power of 
translation from place to place, once considered distinctive of animals, 
we shall find it is possessed by vee:etabl0s as well. This is seen in 
certain organs of reproduction called zoospores^ and in the anilierozoids 
of Alga? and other cpyptogamoiis plants. The movement in all likeli- 
hood depends on the agitation of the fine cilm or threads with which 
these organisms are furnished ; but we are still ignorant as to the 
cause that excites the vibration of the cilia. 
“ As regards. the diet of plants and animals respectively, we have 
already seen that the former cannot take in solid materials. It is far 
different with animals, the most humbly organised of which have the 
power in some way or another of introducing solid food into their 
interior and of digesting it. The nutriment of animals differs, 
therefore, from that of plants physically. Another difference consists 
in its chemical nature. An animal not ouly feeds on solid food, but 
that food is of organic nature ; in other words, the animal enjoys the 
privilege of eating its fellow creatures, dead or alive. A plant is, 
however, not confined absolute^ to inorganic, matter for its diet. It 
thrives upon and indeed requires organic matter, or the prodticts 
of organic matters; but they must, as a rule, be xoaste products, not 
living. Plants manured with purely mineral ingredients not only do 
not thrive, but they are often worse off than others of the same kind 
that are not manured at all. It is pretty ‘clear, then, that plants 
cannot live solely upon inorganic materials. Our every day experience 
shows us, on the other hand, that animals cannot live exclusively upon 
organic materials. If we want to feed a plant so as to ensure the 
greatest amount of vigour, we give it organic food in the shape of 
manure. If we want to digest our own food we take a sufficiency of 
salt ; we give chalk to our chickens, lime and iron to the weak and 
delicate of our own species. 
“The gaseous food of plants has already been alluded to. It 
remains to notice the breathing process in plants and animals 
respectively. 
“ Kespiratiou is an interchange of gases, and this interchange is 
effected in animals by means of cavities, lungs, gills, or tracheae ; but 
whatever shape the bicathing apparatus assumes, the ultimate result is 
that the air inspired or expired is passed through a membrane. AVe 
know from the researches of Graham that membranes act the part of 
filters, allowing some gases to pass and retaining others, according to 
the nature of the filter and of the gases. 
“ In the lower animals, and in plants, we have no special lungs or 
gills. There are tracheae in plants, but they are not specially sub- 
servient to respiration ; and there is covering the whole surface a 
thin membranous cuticle or epidermis. This cuticle acta as a filter, 
allowing the gases to pass by diffusion into or out of the leaf. In 
addition, there is a direct passage of gases through the stomata. 
“ In a general sense, then, the mechanism of respiration is the 
same in animals and plants. The movement of the leaves by the wind 
probably serve the same purpose as that fulfilled by the muscles of 
