392 THE MOUNTAIN. 



or spinal cord, but mantles of stone, wings of purple and gold, 

 gauze and silk, indurated skin-skeletons outside, crusty hides 

 of lime and leather, with strange articulations, hardest shells, 

 or mucous films, in short, of mollusk, lobster, butterfly, and 

 polypus. Is there no end to this whirl ? where do these animal 

 vortices stop ? On dances the enchanted cell, down, down 

 through crawling worm and writhing zoophyte, to the incon- 

 ceivable protozoa, " organization, type of a cell,"* where the 

 animal shakes hands with the vegetable, and it is asked, which 

 is the plant and which is the animal, while the microscope 

 stands aghast over a hideous simplicity, a fearful unity, and 

 that bridge, sharper a thousand times than the finest sword, 

 is passed between "man and nothingness," and creation 

 stands her last trick detected, her last joke confessed, "in- 

 finitude within, infinitude without." 



Siebold remarks : " The invertebrate animals are organ- 

 ized after various types, the limits of which are not always 

 clearly defined. There is, therefore, a greater number of 

 classes among them than among the vertebrates. But, as 

 the details of their organization are yet but imperfectly 

 known, they have not been satisfactorily classified in a natu- 

 ral manner." 



The arrangement of the invertebrates in the Animal 

 Kingdom of Baron Cuvier, is the classification which has 

 been in general use, and is familiar to all. This is the 

 distribution into divisions of Animalia mollusca, or soft 

 animals, Animalia articulata, or articulated animals, and 

 Animalia radiata, or radiated animals. 



This generalization has been used by the greater number 

 of writers on the subject, and its clever nomenclature has 

 become mingled with most of the literature of that depart- 

 ment. The microscope, and more recent scientific observers, 

 have given more elaborate generalizations in this division 



* "Siebold, Kolliker, and others, have taken the ground that in- 

 dividual animal forms may be unicellular ; or, in other words, that 

 an animal may be composed of only a single cell." Burnett's Intro- 

 ductory Note to the Infusoria. 



