648 Blackman .— The Primitive Algae 
and their allies since Wille’s articles were published. In this 
first article I propose to deal with such of this work as 
bears on the phylogenetic relations of the primitive forms of 
green and of brown Algae, and also to give an outline of 
their respective affinities with the Flagellata. 
The literature of this subject is very much scattered, im¬ 
portant work coming alike from Scandinavia, Russia, Hungary, 
and Italy; and as no general account of it has yet been pub¬ 
lished, I may be allowed perhaps to treat it at some length. 
I have endeavoured to weave the different lines of work 
into one continuous account, so that inevitably I have had to 
ignore a certain number of opposed theories and to introduce 
some for which I alone am responsible. 
The first section consists of an introductory sketch of the 
probable inter-relations of the forms which make up the 
Chlorophyceae, and leads to the conclusion that they are all 
derived from a Chlamydomonas -like organism. The second 
gives an account of the advance of our knowledge of this im¬ 
portant genus, Chlamydomonas , during the last ten years. 
The third inquires into the evolutionary origin of this primary 
plant type, and contains a sketch of the group Flagellata. 
The fourth section is devoted to a phylum of green Algae, for 
which an origin quite apart from that of the Chlorophyceae 
proper is suggested. The fifth gives a brief account of the 
recently described primitive forms of the brown Algae, and of 
their probable evolution also from the Flagellata. 
An outline of Wille’s classification of the genera with which 
we shall deal is given on p. 649, and this will serve as a 
starting-point for our treatment. Forms not mentioned by 
Wille are added in italics, and those which must now be moved 
elsewhere are placed in brackets. 
The phylogenetic views propounded in the various sections 
have been worked into one general scheme, which will be 
found on pp. 684, 685. The lower part is occupied by the 
Flagellata, and the dotted zone right across includes the 
forms on the border line, the position of which is still open 
to question. 
