87 
The Classification of the Algae. 
success. Later, the Swedish algologists, Luther and Bohlin, have 
given good reason for supposing that the Flagellata gave rise to 
true algal descendants, not along one line only, but along several 
and finally Senn’s treatment of the Flagellata in the “Pflanzen- 
familien,” though he does not accept Bohlin’s conclusions, has 
further served to emphasise the importance of this group as 
precursors of the Algae. 
Professor Oltmanns’ treatment of the Flagellata is based on 
that of Klebs and Senn. That curious “algal Flagellate” Hydrurus, 
he includes in the Chrysomonadineae (the yellow-brown division of 
the Flagellata) and such forms as Phceocystis, Pliceococcus and even 
Phccotlianmion (which in certain respects is quite a highly developed 
Alga and was actually placed by Wille among the pure green 
filamentous forms in the Chroolepidea?) are treated as an appendix 
to the yellow-brown Flagellates. This is indeed theleastobjectionable 
position for these lowly-organized fixed brown forms at present, 
since their cell-structure is in most cases typically flagellate. There 
is much to be said for considering them as efforts in the direction of 
algal evolution from a stock of Flagellates which ultimately gave 
rise to the Phjeophyceae proper, (Brown seaweeds), especially as 
the motile cell in these simple forms often shows the typical 
one-sided (monosymmetrical) structure characteristic of the 
zoospores and gametes of the Phaeophyceae; and this view is 
strengthened by the great importance which we must now attach, 
as a result mainly of the studies of the Swedish algologists to the 
characters of the algal motile cell. For the time being we are 
inclined to agree with Professor Oltmanns’ view (p. 13) that it is 
too early to place these simple forms actually with the Phaeophycese, 
and they are too miscellaneous a collection to be given a family of 
their own. 
The series of Heterokontae (spelt by our author with a c) of 
Bohlin is, we are glad to see, completely accepted by Professor 
Oltmanns. We regard the building up of this series out of many 
well-known and some newly discovered forms, a building up which 
was the cumulative work of Borzi, Lagerheim, Luther and finally 
Bohlin, as quite the most brilliant and notable advance in the 
morphology and classification of the Green Algae that has been made 
for many years. The striking cytological characters in which the 
forms assigned to this series agree :—their yellow-green pigment, con¬ 
tained usually in several discoid chromatophores without pyrenoids, 
the formation of oil instead of starch as an assimilative product, and 
