336 VIEW OF NATURE. 



In the orders of animals next to man, we find the senses of 

 sight, touch, taste and smell equally perfect as those possessed 

 by him, and in some cases, they are even more acute ; but as 

 we proceed downwards through the gradations of animal exist- 

 ence, we perceive the number and acuteness of the senses to 

 diminish we find some beings with but four senses, some with 

 three, others with two, and lastly, in the Zoophites, we find 

 only the sense of touch, and that so faintly exhibited as almost 

 to lead us to doubt its existence. 



Let us, after these observations, return to the distinction 

 between animals and vegetables. You now perceive that al- 

 though you would find no difficulty with regard to a nightin- 

 gale and a rose, to discover to which of the kingdoms of nature 

 they belong ; yet with respect to a sponge or coral, and a 

 mushroom or a lichen, it would be somewhat difficult, without 

 a previous knowledge of their classification, to say which is 

 called animal, and which vegetable, or to give the distinctions 

 between them. We have seen among the zoophites, that the 

 polypus may be increased by cutting shoots and engrafting 

 them upon other animals, in the same manner as vegetables 

 may be increased. 



With respect to sensation, some plants discover this, appa- 

 rently even in a greater degree than some of the last orders of 

 animals ; the sensitive plant shrinks from the touch ; the Dio- 

 nea suddenly closes its leaves upon the insect which touches 

 them ; the leaves of plants follow the direction of light, in 

 order to present their upper surfaces to its influence ; this you 

 can observe in flower pots placed by a window. The seed of 

 a plant, in whatever situation it may be placed in the earth, 

 always sends its root downwards, and its stem upwards ; in 

 these cases, does there not seem as much appearance of sensa- 

 tion and instinct, and even more than in the lower orders of 

 animals ? 



We find then, that the possession, or want of instinct, does 

 not constitute a mark of distinction between animals and 

 plants. , 



Some have attempted to draw a line of distinction, by con- 

 sidering, that locomotion, or the power of changing place, be- 

 longs to animals only ; but this criterion seems to fail, since we 

 find animals fixed io the bottom of the sea, or growing upon 

 rocks, and plants moving upon the surface of the water. 



Another mark of distinction has been given, in the supposed 

 presence of nitrogen in animals, detected by a peculiar odour 



Senses of the orders of animals inferior to man Sensation seems to be pos- 

 sessed by some plants Instinct not peculiar to animals Locomotion 



Nitrogen. 



