98 CJiodat . — On the Polymorphism of the Green 
Green Algae, to discover the archetypes in the chaos of the 
Chlorophyceae.’ 
Sachs 1 will for the present only recognize as archetypes the 
Cyanophyceae, Phaeophyceae, Rhodophyceae, Conjugatae 
(with Bacillariaceae), Siphoneae, and Archegoniatae. He 
includes the order Coleochaeteae in the Archegoniatae, 
separating it from the Green Algae — an arrangement which 
I am unable to accept, for reasons presently to be explained. 
One cannot too strenuously oppose such a conception of 
the archetypes. It is very clearly evident that the most 
striking resemblance exists between the Phaeophyceae and 
the Chlorophyceae ; the production of zoospores the origin 
and development of sexuality, and the progressive develop- 
ment of the thallus occur in a similar manner in both groups. 
Their systematic rank as archetypes is of no higher value 
than that of the Bryophyta compared with the Pteridophyta. 
Whilst agreeing with Sachs in regarding the Conjugatae 
as forming a very distinct order, I cannot go so far as he 
does when he removes them from the Chlorophyceae and 
groups them with the Bacillariaceae, a quite distinct and 
remote order belonging to the Phaeophyceae. 
Just as we find in the Archegoniatae several distinct groups, 
such as the Mosses, Ferns, Equisetaceae and Lycopodineae, 
which cannot at present be traced back to any known common 
ancestor, so there are in the Chlorophyceae such orders as 
Oedogoniaceae, Sphaeropleaceae, Conjugatae, and Siphoneae, 
which are only separated from the others by certain tendencies 
already known in the whole group. 
The Conjugatae, for example, are chiefly characterized by the 
mode of their fertilization. Conjugation, however, exists in 
certain species of Chlamydojnonas (C. Braunii ) 2 . Very highly 
differentiated chromatophores are also to be found in the Vol- 
vocineae 3 , and the zygotes of these are not very different from 
1 Loc. cit., p. 201. 
2 Gorochankin, Beitrage zur Kenntniss der Morphologie und Systematik der 
Chlamydomonaden, Bull. Soc. Nat. Moscou, No. 3, 1890. 
3 See the above-quoted paper ; also Schmidle, Chlamydomonas Kleinii, Flora, 
