Inter-Relationships of Protista and Primitive Fungi. 99 
The general characters of the Flagellata as a class were 
treated in the earlier paper dealing with the coloured forms and 
their relationships to the primitive Algae (Cavers, 1913, pp. 30-32), 
hence we need consider here in detail only the colourless Flagellate 
groups. These— apart from forms which are obviously colourless 
heterotrophie derivatives of coloured types classed with the 
Chrysomonads, etc.—belong to Senn’s divisions Pantostomatineae, 
Distomatineae and Protomastigineae. Specialised forms like the 
Cystoflagellata (Noctilucaceae) and Haemoflagellata (Trypanosomes) 
need not be dealt with, since we are concerned with those Protista 
which appear to be significant in connexion with the relationships 
of the primitive Fungi. 
Different writers have proposed various classifications of the 
colourless Flagellata, but in practically every recent system we find 
placed at the base of the series the group which Senn terms the 
Pantostomatineae, and there is general agreement that the forms 
included here may be regarded as the most primitive types, from 
which the remaining Flagellata have probably arisen. Hartog 
(1909), after separating off the Dinoflagellata (Peridiniales) and in 
a later scheme (1910-11) also the Cystoflagellata (Noctilucaceae), 
makes a primary division into Rhizoflagellata (Pantostomatineae) 
and Euflagellata ; the latter term is used by Willey and Hickson 
(1909) to include all the Flagellata except the Phytoflagellata 
(Volvocales), Dinoflagellata, Cystoflagellata and Silicoflagellata, 
but they also place Senn’s Pantostomatineae at the base of the 
Flagellata. 
The Pantostomatineae, or Rhizoflagellata, are characterised 
by the fact that solid food may be ingested at any point of the body 
in an amoeboid fashion, i.e., by means of pseudopodia, the body 
being naked and the periplast represented only by an alveolar layer 
of protoplasm ( Multicilia ) or as ectoplasm covered by a very thin 
pellicle ( Mastigainceba ). They are divided into two families. In 
the Holomastigaceae the body shows multilateral symmetry, being 
spherical with flagella scattered all over the surface, food is ingested 
by pseudopodia and also defecated at all points, and locomotion is 
rotatory. This family includes the free-living genus Multicilia with 
one marine and one freshwater species, the latter (M. lacustris, 
Fig. 1, A) having numerous nuclei and differing in this respect from 
other Flagellata (excepting the Trypanosomes which are binucleate), 
and the closely related genus Grassia 1 which occurs in the alimentary 
canal and blood of frogs ; the only known method of reproduction 
is by median constriction and subsequent fission of the body. 
The second family, the Riiizomastigaceae, is larger and its 
members have only one or two flagella, but some of them are 
remarkably polymorphic in the sense that they may either live as 
free-swimming forms or may be amoeboid or heliozooid (i.e., spherical 
with numerous fine radiating filamentous pseudopodia as in Heliozoa 
like Actinophrys) ; in the two latter conditions the body may be fixed 
to a substratum by a fine basal pseudopodial stalk, but in any case 
the flagella are retained through the amoeboid or heliozooid phase. 
1 According to Schuberg (Biol. Centralbl., Bd. 9 1909), however, the 
bodies occurring in the alimentary canal of frogs and described as Grassia by 
Fisch (Zeitschr. f. wiss. Zool., Bd. 42, 1885) are merely detached and deformed 
ciliated epithelium cells. 
