63 



Fig. 71. 



Blossom - 

 diagram of 

 Cephalotus 

 follicularis. 



nature. Among the lower animals the most beautiful examples are 

 found in the Hexacoralla; especially the lime-forma- 

 tions of Cyathina cylindrica, Stephanophyllia complicata 

 and elegans (fig. 12 on Table 7), of Astrocyathus para- 

 doxus (fig. 10, Table 7) etc., are, according to Haeckel's 

 drawings, good illustrations of this symmetry and 

 excellent instances of these pretty forms. In fig. 77 the 

 blossom-diagram of Cephalotus follicularis has been 

 reproduced, while in fig. 72 a drawing of the fruit of 



Aubletia caseolaris is given and in fig. 73 a fruit of Badamia 



Commersoni, (after 



Gaertner), both 



as good botanical 



examples of this 



same symmetry. 

 It also seems, 



that among the 



Ascidiae represen- 

 tatives of this 



class are found : 



evidently Molgula 



tubulosa, and Sy- 



noecum turgens may 



be reckoned among this kind of symmetrical objects. 



Of the groups with an axis A n of higher value for n than 6, it is 



not easy to find good 



examples in nature. 



j^ f Perhaps among the 



Qy^S^>\ Hexacoralla the form 

 A*W jlm %*\ 



f / \\ * Leptocyathus elegans 



H||t ||*i .'. (Haeckel) may be 



mlKJ^ mentioned as a repre- 



^S^ ^^fck' sentative of the group 



r v 



U 22. 



Of the groups , 

 which of course give 

 only a series of new 

 forms for even values of n, no instances among plants and animals 

 have been found up till now. 



As an illustration of polyhedra of this kind, in fig. 74 and 75 



Fig. 72. 

 Fruit of Aubletia caseolaris. 



Fig. 73. 

 Fruit of Badamia Commersoni. 



