FORMS OF LIFE 



intricate flinty structures are merely the plastidules or 

 micella, the molecular and microscopically invisible con- 

 stituents of the soft viscous plasm (sarcode). 



The configuration of the histona differs essentially 

 from that of the protists, since in the case of the latter 

 the simple unicellular body produces for itself alone the 

 whole form and vital action of the organism, while in 

 the histona this is done by the cell state, or the social 

 combination of a number of different cells, which make 

 up the tissue body. Hence the ideal type which we can 

 always define in the actual histonal form has quite a 

 different significance from that in the unicellular pro- 

 tists. In the latter we find the utmost diversity in the 

 configuration of the independent living cells and the 

 protective cover it forms ; among the histona the number 

 of fundamental forms is limited. It is true that the 

 cells themselves which make up the tissues may exhibit 

 a great variety in form and structure; but the number 

 of the different tissues which they make up is small, and 

 so is the number of ideal types exhibited by the organism 

 they combine to form — the sprout {culmus) in the plant 

 kingdom and the person in the animal kingdom. The 

 same may be said of the stock (cormus) in both king- 

 doms — that is to say, of the higher individual unity 

 which is constituted by the union of several sprouts or 

 persons. 



The two classes of fundamental forms which are espe- 

 cially found in the plant sprouts or the animal persons 

 are the radial and bilateral. The one is determined by 

 the stationary life, the other by free movement in a cer- 

 tain attitude and direction (swimming in water or creep- 

 ing on the ground). Hence we find the radial form (as 

 pyramidal) predominant in the blooms and fruits of the 

 metaphyta, and the persons of the polyps, corals, and 

 regular echinoderms. On the other hand, the bilateral 

 or dorsi ventral form preponderates in most free -moving 



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