Flagellata and Primitive Algce. 
IJ 5 
of the protoplasm is extruded from a pore, this amoeboid mass being used up 
in the formation of the cyst membrane; 13 and 14 are different views of the 
fully formed cyst. 15 to 18, Chrysococcus rufescetis Klebs : 15, a motile cell, in 
optical section, showing projection of the flagellum through a pore in the thick 
perisarc ; 16, division of the protoplast; 17, escape of a daughter-cell; 
18, free daughter-cell, before formation of perisarc. 19, Microglena punctifeva 
Ehrb., showing the vacuole system. 20, Mallomonas litomesa Stokes, with 
flinty processes at anterior and posterior ends of the cell, 21, Mallotnonas 
acaroides Ehrb., with similar processes nearly covering the cell. 22, 
Mallomonas pulcherrima Stokes, showing in part the reticulate sculpture 
of the perisarc. 23 to 25, Stylococcus aureus Chodat: two stages of division 
in 24 and 25. 26 to 30, Chrysopyxis bipes Stein : in 26 the flagellum is forked; 
27 shows longitudinal division into two daughter-cells ; 28 and 29, a daughter¬ 
cell with elongating posterior process for attachment—in 30 this process has 
wound around a Zygnema filament, part of which is seen in transverse section 
at the base of the sessile flask-like perisarc. 31, Lagynion Scherffeli Pascher. 
32, Heterolagynion Oedogonii Pascher : to the left of the stout motionless flagellum 
is a short blunt pseudopodium (pseud.) ; within the stout perisarc the protoplasm 
contains a nucleus (nu.J, a food vacuole (f.v.), two contractile vacuoles (c.v.), 
and two leucosin masses (leuc.) 33, Pedinella hexacostata Wys., with four stiff 
bristles at the base of the flagellum ; on the right is an amoeboid pseudopodium 
containing a food vacuole. 34, Cyrtophora pedicellata Pascher, showing the 
central flagellum, the stout nodulose tentacles, and several pseudopodial pro¬ 
cesses at the anterior end of the protoplast. 35, Palatinella cyrtophora Laut., 
with short flagellum in the centre of the ring of tentacles. 36, Chrysosphcerella 
longispina Laut., a motile coenobium of Chroniulina- like cells, each with two long 
flinty processes exserted from cup-like outgrowths of the periplast. 37 to 41, 
Hydrurus feetidus (Vauch.) Kirchner : 37, a motile cell or zoogonidium; 38, 
motionless cell, which becomes attached by a gelatinous stalk (39) and by 
division (39) gives rise to the branching colony, a portion of which is shown 
in 41. 
1, 2, 10, 15 to 19, 21, 37 to 40, from Klebs; 3 to 9, from Woronin ; 11 to 
14, from Cienkowsky ; 20, 22, from Stokes ; 23 to 25, from Chodat; 26 to 30, 
from Stein; 31, 32, 34, from Pascher; 33, from Wysotzki; (35, 36, from 
Lauterborn ; 41, from Berthold. 
Hydrurus and other palmelloid Chrysomonads have been 
regarded by some writers as belonging to the Phaeophyaceas, on 
account of the dominance of the palmella stage in the life history, 
but apart from the fact that various degrees of elaboration of this 
stage have been observed in undoubted Flagellates, the terminal 
insertion of the flagella in the lower Chrysomonads, as compared 
with the characteristic lateral flagella of the Brown Algae, seems to 
form an insuperable obstacle to the derivation of the Phaeophyceae 
from these Chrysomonads. Despite the dominance and elaboration 
of its palmella stage, Hydrurus can hardly be said to have crossed 
the “border-line” between Flagellates and Algae; it is simply a 
Flagellate, allied closely to the lower Chrysomonads, and represents 
the culmination of a line of palmelloid forms arising from types like 
Chrysapsis and Nannochrysis. The “ Volvocine tendency ” shown 
in Chroniulina Hokeana is carried further in Chrysostephanosphcera , 
recently discovered by Scherffel; here the coenobium consists of 
sixteen cells arranged as in Stephanosphcera on the equator of a 
globular gelatinous mass, but later a palmelloid state is produced 
in which each cell has its own mucilaginous envelope. 
Further elaboration in the external and internal characters of 
the cell is seen in the small family of Mallomonadaceae, consisting 
of the two free-living genera Mallomonas and Microglena and the 
colonial genus Chrysosphcerella. In Mallomonas (Fig. 5, 20-22) the 
