79 
Flagellata and Primitive Alger. 
classification based by Blackman and Tansley (7) upon the principles 
set forth in that paper; also to the systematic works on Algae by 
Oltmanns (95), West (146), and Lotsy (89), in which due prominence 
is given to modern views of Algal phylogeny. More recently, 
Fritsch (46) has published a valuable paper, in which is included a 
useful bibliography; while Pavillard (114) has contributed a resume 
of some modern work on Vegetable Protistology—though his “revue 
rapide” omits entirely the Brown Flagellata and lower Brown 
Algae, on which some remarkably interesting work has been published 
during the last few years. 
The relationships of the three lines of Flagellate-Algal descent 
here suggested are indicated in the accompanying Table A, a fuller 
explanation of which will be given later. 
Archegoniatae 
Volvocaceae Ulotrichales, etc. Siphoneae Phaeophyceae 
T T T T 
Volvocine Tetraeporine Endosphaerine Phaeocapsaceae 
tendency _tendency 
\ / 
Chlamydomonads 
T 
Polyblepharids 
tendency 
Confervales 
Cryptomonads 
A' 
Chlorosaccus 
Autotrophic Multicilia-like 
Mastigamoeboid Ancestors 
Heterotrophic 
Flagellata 
Table A.—Suggested Phylogeny of (I) the Polyblepharid and Chlamydo- 
monad, (II) the Chloromonad, and (III) the Chrysomonad and Cryptomonad 
lines. For details see text. 
Since 1900, perhaps the greatest advances in the study of those 
Flagellates which are more obviously important in connexion with 
the phylogeny of the Algae have been made among the Chrysomonads 
and Cryptomonads, but before dealing with these we may consider 
some interesting additions to our knowledge of the group of Green 
Algae whose evolution from the Flagellata has, on the whole, been 
most completely worked out—namely, the Volvocales, using this 
name to include the entire series of organisms (the “ Phyto- 
flagellata ” of various zoological writers) representing the transition 
from Flagellate ancestors to the motile unicellular Green Algae 
(Chlamydomonads) and the outcome of the Volvocine tendency 
which leads to the formation of increasingly complex motile 
ccenobia and culminates in Volvox. 
