THE NEW GENEALOGICAL TREE 357 



as a notion in spite ot the fact that it is formed in a rather 

 negative sense: it is not uniform and it includes various 

 categories (the subcellular, hypercellular, and actually also the 

 primarily monocellular forms). 



The System of the Protozoa 



Now w^hen we have draw^n a clear limit between the Proto- 

 phyta and the Protozoa wx must also draw a limit between 

 these and the higher forms. This does not seem to be such 

 a difficult task because it has become clear that no correspond- 

 ing transitional forms have survived till now. We can there- 

 fore still continue to use the name w^hich was introduced 

 some time ago, that of the Protozoa (Goldtuss, 1820) even if 

 this word has not been most fortunately selected and in spite 

 of the fact that in the mea;ntime its exact meaning has been 

 changed several times. The first sub -kingdom can therefore 

 preserve its old name of Protozoa until it is changed by an 

 eventual international decision. Few attempts only have been 

 made to construct an animal system which do not include 

 the taxon Protozoa (cf. the system proposed by Ulrich, 1951). 



Scholars have usually been satisfied to give the rank of 

 classes to the subdivisions of the Protozoa. Usually there are 

 from four to five classes; this is dependent on the fact of 

 whether we consider the Sporozoa s. lat. as one or as two 

 classes (Telosporidia and Amoebosporidia, according to Dof- 

 lein and Dogiel, 1937). The first scholar w^ho proposed that 

 the subregnum Protozoa should be divided into two larger 

 subgroups was B. Hatschek (1888). He proposed in his 

 famous 'Lehrhuch der Zoologie (unfortunately never completely 

 published), that the first three large groups, i.e. Flagellata, 

 Rhizopoda, and Sporozoa, should be included in the phylum 

 Cytomorpha while each of these large groups should be given 

 the category of a cladus (thus a higher category than that of 

 a class). The phylum Cytoidea (i.e. "similar to the cells," now 

 24 



