THE WONDERS OF LIFE 



graph (Challenger Report, vol. xviii.). On the other 

 hand, the monera, at the lowest stage of organic life, 

 the structureless organisms without organs that live 

 on the very frontier of the inorganic world, are very 

 simple. Especially interesting in this connection are 

 the chromacea, which have hitherto been so unde- 

 servedly and so incomprehensibly neglected. Among 

 the well-known and widely distributed chroococcacea, 

 the chroococcus, coelosphaerium, and aphanocapsa are 

 quite the most primitive of all organisms known to us 

 — and at the same time the organisms that enable us 

 best to understand the origin of life by spontaneous 

 generation (archigony). The whole organism is merely 

 a tiny, bluish-green globule of plasm, without any struct- 

 ure, or only surrounded by a thin membrane; its funda- 

 mental form is the simplest of all, the centraxial smooth 

 sphere. Next to these are the oscillaria and nostochina, 

 social chromacea, which have the appearance of thin, 

 bluish-green threads. They consist of simple primitive 

 (unnucleated) cells joined to each other; they seem often 

 to be flattened into a discoid shape as a result of close 

 conjunction. Many protists are found in two conditions, 

 one mobile with very varied and changeable forms, and 

 one stationary with a globular shape. But when the 

 separate living cell begins to form a firm skeleton or pro- 

 tective cover for itself, it may assume the most varied 

 and often most complicated forms. In this respect the 

 class of the radiolaria among the protozoa, and the class 

 of the diatomes among the protophyta (both of which 

 have flinty shells), surpass all the other groups of the 

 diversified realm of the protists. In my Art-forms in 

 Nature I have given a selection of their most beautiful 

 forms (diatomes, A-f, 4, 84; radiolaria, A-f, i, 11, 21, 

 22, 31, 41, 51, 61, 71, 95). The most remarkable and 

 most important fact about them is that the artistic 

 builders of these wonderful and often very ingenious and 



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