Review. 
49 
Griffith’s work is regarded as definitely establishing Glaticocystis as 
a member of the Blue-green Algae (p. 452), but until its cytological 
characters have been compared with those of the species of 
Oocystis, we do not consider that a final conclusion is possible. 
The statement on p. 3, as to the blue colouration of the sheath 
with chlor-zinc-iodide in Schizothrix, is misleading, as this 
character is not restricted to the genus mentioned, being 
encountered also in Lyngbya, Phormidium, etc. It is also our 
experience that the heterocysts are quite commonly deeply 
pigmented in tropical Myxophyceae (cf. p. 17). 
In the able account of the Peridineae which follows, the author 
adpots Kofoid’s terminology for the plates of the Peridiniaceae. 
The omission of Murray and Whitting’s paper from the biblio¬ 
graphy is curious, and we are also astonished to find no reference 
to Pascher’s (cf. Ber. Deutsch. Bot. Ges., XXXII., 1914, p. 151) 
description of a filamentous member of the Peridineae ( Dinothrix ) 
with swarmers of the Gymnodinium- type. Although Pascher’s 
communication is only a brief, preliminary one, and may rest on a 
misconception, it is surely important enough to deserve some 
attention. 
The description of the Bacillariales is again quite excellent 
and the choice of illustrations admirable. A brief section dealing 
with methods of culture will prove very useful, and a similar one 
might well have been incorporated in the accounts of the previous 
groups. In discussing the affinities of Diatoms (pp. 119, 120) 
Pascher’s views ( loc . cit., pp. 146, 147) on relationships with 
Heterokontae and Chrysopyhceae might well have found mention. 
It is to be regretted that the author adopts a different treat¬ 
ment, namely that of partition into numerous short sections, in the 
case of the Chlorophyceae, since the many points of contact 
between the different subdivisions are thereby much obscured, so 
that it is difficult to obtain a clear view of the group as a whole. 
Except in the excellent account of the Conjugatae, this is often 
only too apparent. Many will be inclined to disagree with the 
author’s inclusion of the Heterokontae as one of the four sub¬ 
divisions of the Chlorophyceae. All the evidence points to the 
Heterokontae being a phylogenetic line quite separate from that of 
the other green Algae. We also regard the adoption of the terms 
Akontae and Stephanokontae as undesirable, since there is nothing 
to show that the ancestry of these groups is really distinct from that 
of the Isokontae, of which they appear to be early offshoots. The 
absence of motile reproductive cells in the Conjugatae is paralleled 
in other series of the Isokontae, and the large size of the Oedogoni- 
aceous zoospore is probably responsible for its numerous cilia. 
In the subdivision of the Isokontae all the unicellular and 
colonial types are included in one order, the Protococcales. The 
author’s disinclination to recognise the motile forms as a separate 
series, the Volvocales (as advocated by Pascher and others), is not 
altogether to be reconciled with the adoption of Ulvales and 
Schizogoniales as distinct subdivisions. The former appear merely 
as a specialised branch of the Ulotrichales. The axile chloroplasts 
and other peculiarities of the Schizogoniales do not seem to warrant 
separation from the Ulotrichales, since plastids of this type are 
