ROLL CALL 



77 



Characteristics: Seeds enclosed by a case (ovary), so that pollen Rrain 

 does not reach the ovule but rests on surface of carpel ; closure to form 

 case probably arose by folding together of edges of megasporophyll {carpd) ; 

 pollen received on special organ (stigma) at tip of ovary. Members of 

 this group probably were derived from gymnosperm stock ; now number 

 135,000 species and are subdivided into dicotyledons and monocotyledons 

 which may be separated by the following ciiaracteristics : 



CLASSIFICATION OF THE ANIMAL KINGDOM 



(mainly after Hegner) 



All members of the animal kingdom are characteristically free-moving organ- 

 isms; generally capable of assimilating organic foods; rarely possessing chloro- 

 phyll ; cell membranes composed of protoplasm or proteins. 



PHYLUM I — PROTOZOA — One-celled animals. 



Characteristics : Single cells or colonies of loosely aggregated unspecial- 

 ized cells ; rarely differentiated into germ cells ; 8500 species. 



Class I — Sarcodixa — Naked protozoa (Ameba,^ Arcella, Radiolaria). 

 Characteristics : Locomotion by means of pseudopodia. 



Class II — Mastigophora — Flagellate protozoa (Euglena, Trypanosoma). 

 Characteristics : Locomotion by means of flagella. 



Class III — Sporozoa — Parasitic protozoa (Lankesieria, Myxosporidia, Plas- 

 modium). 

 Characteristics : Xo organs of locomotion in adults ; endo-parasites repnn 

 ducing by schizogony and spore formation. 



Class IV — Infusoria — Ciliate protozoa (Vorticella, Stentor, Stylorjychia, 

 Paramecium). 

 Characteristics : Locomotion by means of cilia. 



1 See footnote at beginning of classification of Plant Kingiioni. 



