Flagellata and Primitive Algce. i19 
cine,” and the solitary and dendroid “ ehoanoflagellate ” types 
met with in the colourless Pantostomatineae and Protomastigineae 
on one hand and the Chrysomonadineae on the other are to be 
interpreted as examples of parallel developments, or whether, as 
suggested by Pascher and Scherffel, they indicate derivation of 
part at any rate of the colourless Flagellate families from Chryso- 
monads, the trend of recent work on the Brown Flagellata is 
decidedly against the view that the Chrysomonads comprised in 
families Chromulinales, Isochrysidales, and Ochromonadales have 
given rise to the Brown Algae. 
The case appears to be quite different with the fourth Chryso- 
monad order, the Phaeochrysidales or Cryptomonads, which are 
distinguished by the lateral insertion of the two flagella. The 
simplest forms are Pascher’s new genera Cryptochrysis and Proto- 
chrysis (103) ; Wysotzkia (hitherto placed in the Isochrysidales) ; 
and N ephroselmis (Senn, 136), which Wille (150) includes in the 
Volvocaceae. Senn (135) defines the Cryptomonads as having an 
ovoid and flattened body, with two equal flagella arising just behind 
the anterior end from a groove which is continued into a gullet-like 
cavity, and having one or two contractile vacuoles which are not 
coordinated into a pulsating system. According to Senn they are 
also further differentiated from the Chrysomonads by producing 
starch, or, at any rate, a refractive solid carbohydrate. The 
researches of Pascher and others have shown, however, that the 
Cryptomonads, though a highly specialised group, cannot be set 
apart from the Chrysomonads, as a separate group of the Flagellata, 
and that they have arisen from the Chrysomonads by further internal 
differention of the protoplast, accompanied by a shifting of the 
flagella from a terminal to a lateral position. In Wysotzkia (Fig. 
7, 3,4), the posterior end of the protoplast, behind the two chromato- 
phores, is naked and capable of amoeboid movement. In Crypto¬ 
chrysis (Fig. 7, 2), the lateral insertion of the flagella is more 
marked than in Wysotzkia, the flagella arising from a deep longitu¬ 
dinal groove which is about half the length of the body and is 
covered with minute granules; nutrition is purely holophytic and 
the assimilate consists of disc-like grains giving a reddish violet 
colour with iodine ; division takes place in the motile state, and is 
longitudinal. 
Cryptochrysis appears to be the most primitive Cryptomonad 
at present known ; Wysotzkia, though simpler in some respects, 
undergoes transverse division, and is adapted for partial or 
facultative holozoic nutrition. Nephroselmis and Protochrysis 
differ from these genera, and indeed from the remaining Crypto¬ 
monads, in that the groove is transverse and occupies the middle 
of the protoplast, so that the flagella arise from the middle of the 
concave side of the body ; in Nephroselmis there is a single chroma- 
tophore which follows the outline of the body and is interrupted 
only at the point of emergence of the flagella, and division occurs 
in the motile condition, whereas in Protochrysis (Fig. 7, /), there 
are two chromatophores, and division occurs after the cells have 
become rounded off and invested in mucilage, a four- or eight- 
celled colony being formed by repeated division in this palmella- 
state. In Cryptomonas (Fig. 7, 5 — 7), the groove found in the 
