Review. 
90 
briefly referred to, is increased by the fact (alluded to by Bohlin) 
that there is apparently no evidence of zoospores having increased 
the number of their cilia in the course of descent. There are in 
fact actually no transitional forms between the types of ciliation 
described, unless a certain amount of variation in length of the 
shorter flagellum of the Heterokontan type (in which the two flagella 
are sometimes of almost equal length) and the frequent occurrence 
of four flagella in the Isokontae can be so considered. 
It is further increased by the parallel—though less strong- 
evidence of a similar independent derivation from the Flagellata of 
the Brown and the Red Algae. The possible connexion of the former 
with the Chrysomonadineae through forms like Phceothamnion and 
Phceocystis has already been alluded to, and the similarity of their 
motile cells pointed out. There is absolutely no evidence of any 
connexion of the primitive members of the Phaeophyceae proper, e.g. 
the Ectocarpaceae, with green filamentous forms. 
In the case of the red forms the evidence of the connexion of 
the Rhodophyceae with the Flagellates is at present very slight, but 
probably a better case could be made out for such a connexion than 
has yet been done, and we should certainly not be surprised at the 
discovery of further evidence pointing in this direction. 
The net result of all these considerations is the conviction that 
the cytological characters of the primitive motile cell (its chroma- 
tophore, pigment and product of assimilation—handed on of course 
to the immotile cells of the thallus which have taken over the 
vegetative functions in the higher forms) and its locomotor apparatus, 
are of the first importance as constant morphological features and 
therefore as characters to which the greatest taxonomic weight 
must be attributed. We had hoped that Professor Oltmanns 
would have laid more stress than he has done on these points in so 
important a work as the one before us and we trust that he will 
give us a full discussion of the general bearings of these topics in 
his “ Allgemeiner Theil.” 
After a useful summary of those groups of plant-like Flagellates, 
which are not clearly associated with algal forms—the Crypto- 
monadineae, the Euglenaceae, and the Dinoflagellata (with rather a 
full notice of Schtitt’s work on the cell-wall, etc. of the last named) 
Professor Oltmanns proceeds to treat the Conjugatae and the Diatoms 
together under the name Acontae, a term introduced in the 
“ Revision of the Classification of the Green Algae ” published in this 
journal in 1902, and reprinted separately in 1903. This is an 
unfortunate proceeding. The term Akontae was intended to 
