FORMS OF LIFE 



going fully into them here. In the present chapter I 

 will only briefly describe those 'features of living things 

 which relate to the difficult question of their ideal funda- 

 mental forms, the laws of their symmetry, and their rela- 

 tion to crystal-formation. I have treated these intricate 

 questions somewhat fully in the last (eleventh) part of 

 Art-forms in Nature. The hundred plates contained in 

 this work may serve as illustrations of morphological 

 relations. In the following pages the respective plates 

 are indicated by the letters A-f, with the number of 

 each. 



The unity of the organic structure, which expresses 

 itself everywhere in the fundamental features of living 

 things and in the chemical composition and constructive 

 power of their plasm, is also seen in the laws of symmetry 

 in their typical forms. The infinite variety of the 

 species may, both in the animal and plant worlds, be 

 reduced to a few principal groups or classes of funda- 

 mental forms, and these show no difference in the 

 two kingdoms (c/. plate 6). The lily has the same 

 regular typical form as the hexaradial coral or anemone 

 (A-f, 9, 49), and the bilateral-radial form is the same in 

 the violet and the sea-urchin (clypeaster, A-f, 30). The 

 dorsiventral or bilateral-symmetrical form of most green 

 leaves is repeated in the frame of most of the higher 

 animals (the coelomaria); the distinction of right and 

 left determines in each the characteristic antithesis of 

 back and belly. 



The distinction between protists and histons is much 

 more important than the familiar division of organisms 

 into plants and animals, in respect of their fundamental 

 forms and their configuration. For the protists, the 

 unicellular organisms (without tissue) exhibit a much 

 greater freedom and variety in the development of their 

 fundamental forms than the histons, the multicellular 

 tissue-forming organisms. In the protists (both pro- 



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