Some Aspects of the Algee. 
A 
J 
to expect any single author to deal exhaustively with the subject in 
this way. 
In dealing with the system of the Algae, a short historical 
summary is given, but the author makes no attempt to undertake 
the laborious and rather useless task of assigning to each writer 
the suggestions original to him which have become incorporated in 
the modern system. 
Professor Oltmanns himself, as was clear from his first volume, 
adheres to the main fundamental principles of the Swedish 
algologists, who hold that the structure of the algal cell, and 
especially of the different types of zoospore, which are to be 
regarded as survivals of the different primitive flagellate forms from 
which the various groups have been derived, is the basis on which 
the primary division of algal forms should rest. The roots of the 
various algal series are thus found among Protista, and it is 
impossible to lay down precise limits as to where the Flagellata end 
and the Alga; proper begin. On each of these phylogenetic series 
sexuality (in the sense of gamogenesis) has been acquired, some¬ 
times more than once on different branches of the individual series; 
and the sexual process nearly always shews a progress from isogamy 
to oogamy. Although our author anticipates that these views will 
awaken doubt and even contradiction, for our own part we have not 
the least misgiving in considering them at the present time perfectly 
well established principles upon which all further advance must be 
based. At the same time Professor Oltmanns has a wise word of 
warning to the effect that all the characters of the cell must be 
taken into account in making the primary divisions; and although 
colour and cilia are apparently the most important from a taxonomic 
standpoint, there is, of course, no a priori barrier to the evolution of 
a multi-ciliate from a bi-ciliate zoospore, nor of a red or brown from 
a green cell. Something of this sort has apparently happened in 
the Peridineae. 
Concerning the actual system adopted by Professor Oltmanns 
it is not necessary to say much here, since the principal points in 
which we differ from him have been fully discussed in our review of 
the first part of the present work. 1 We may, however, again refer 
to the undesirability of grouping the Diatoms and the Conjugate 
together under the title of Akonte (a word which was introduced 
for the Conjugate alone) whatever views may be held as to a possible 
common origin. Professor Oltmanns himself admits, in a footnote, 
r New Phvtoi.ogist, loc. cit. 
to 
