EEPORT ON THE RADIOLARIA. 



form of the central capsule is always monaxon (with a vertical allopolar main axis) and 

 generally spheroidal ; that of the skeleton is very varied. 



10. Synopsis of the Subclasses and Legions : — 



11. Individuality of the Radiolaria. — Like other Protozoa the Eadiolaria are uni- 

 cellular organisms, the whole fully developed organisation of which falls under the 

 category of a single cell, both morphologically and physiologically. Since this view is 

 based upon the composition of the individual body out of two different morphological 

 elements, nucleus and protoplasm, it is at once justified in the case of the majority of 

 Eadiolaria, in which the plasmatic body encloses only a single nucleus (the so-called 

 " Binnen-Blaschen ") ; such is the case in all the Spumellaria monozoa, Nassellaria and 

 Phaeodaria. This aspect of the case might appear doubtful in those Eadiolaria in which 

 the simple primary cell-nucleus divides early into numerous small secondary nuclei, as is 

 the case in the Spumellaria polyzoa and most Acantharia. Strictly speaking, the 

 multinucleate central capsule should in such cases be regarded as a syncytium; but 

 since the individual unity of the unicellular organism is as clearly defined in these 

 precocious multinuclear Eadiolaria as in the ordinary serotinous forms, the former 

 must be considered unicellular Ehizopods just as are the latter. This mode of regarding 



