CHAPTER XIII 
THE PLANT’S PLACE IN NATURE 
197. The three kingdoms. It has long been the general 
opinion that all natural objects fall readily into three main 
groups or kingdoms—the mineral, the vegetable, and the 
animal. Over a century ago the characteristics of each 
kingdom as understood at the time, were given by Linnzus 
in his famous aphorism: ‘‘ Minerals grow; plants grow and 
live; animals grow, live, and feel.”"* This threefold division 
is still recognized as convenient, and the distinctions given 
are admitted as valid to a considerable extent; but that a 
mineral grows in essentially the same way as a plant, and 
that a plant lacks any quality that is found in all animals, 
would not generally be admitted by the naturalists of to-day. 
In order to understand modern views regarding the plant’s 
place in Nature we need to consider what is meant by grow- 
ing, living, and feeling. 
By “ growth”’ Linnzus seems to have meant merely increase 
in size. Yet is not the enlargement of a seaweed or a fish 
essentially different from the so-called growth of a salt crystal 
in concentrated brine? The crystal gets larger simply by 
additions upon the outside, while the living body increases 
in size by the incorporation within itself of substances de- 
rived from without. Moreover, the crystal as it enlarges 
remains substantially the same throughout, and all the parts 
behave alike. In a growing body on the contrary there is a. 
progressive differentiation of parts and functions. Hence 
we cannot say that a mineral grows in the same sense that 
an organism grows. 
But does not Linnzeus express the differences above in- 
1 Lapides crescunt; vegetabilia crescunt et vivunt; animalia crescunt, 
vivunt et sentiunt. 
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