61 



riorum, of Hydrocharis, and of Trichlogin maritimum are instances 



of this kind. 



In fig. i on Table I (p. 65) we have 

 reproduced the beautiful forms of Porites 

 furcata (Haeckel), one of the class of 

 Hexacoralla, which are celebrated for their 

 graceful forms; and also of the Ascidiae: 

 Botryllus polycyclus (fig. 2). The symmetry 

 of the group C\ is also met with in many 

 Discomedusae : we can find it in the mantles 

 of Pelagia per la, of Drymonema victoria 

 (fig. 3), andin the stomach-section of Undosa 

 undulata (fig. 5), according 

 to Haeckel's drawings (All 

 in Table /) . Cyanea aurelia 

 and many other jelly-fishes 

 too, show this symmetry in 

 a very striking way. Among 

 the Ascidiae, the mantle of Fig 55 



Botryllus Marionis (fig. 4, Blossom-diagram of 



Table /) may be considered Aspidistra eiatior. 

 as an example of this kind. 



Further, in fig. 65 the blossom-diagram of Aspidistra eiatior is 

 reproduced, which also manifests 

 this particular symmetry very 

 beautifully ; another instance is the 

 diagram of Daphne Mezereum. 



Of group C\ innumerable repre- 

 sentatives are found in living na- 

 ture, as well among plants as ani- 

 mals. It even seems as if a certain 

 preference for this special sym- 

 metry may be supposed to exist, 

 which is the more remarkable, since 

 this particular symmetry is quite 

 impossible for crystalline matter 

 In fig. 66 the fruits of Swietenia 

 mahagoni, in fig. 67 that of Ceiba 



pentandra, and in fig. 68 that of Fruit of Swietenia mahagoni. 



Adansonia Baobab, all after Gaertner, are reproduced as good 



Fig. 64. 



Fruit of 

 Canarium decumanum. 



Fig. 66. 

 Fruit of Swietenia 



