MORPHOLOGIE UND BIOLOGIE DER ALGEN 107 
origin of alternation lies hid among the lower organisms. 
The work of Prof. Olimanns is divided into two parts. The first, 
published in 1904, and reviewed at some length in this Journal for 
that year, contains a detailed account of the various Algal types, 
including the Flagellate, to which so important a place is now 
assigned by Wille and others, as a theoretical starting-point for the 
more elaborate Algal forms. It includes, also, the C 
curiously-isolated group to which no certain place is yet assigned, 
and which ig on that account frequently omitted from Algal works. 
Bacteria. Th thod of the first part is descriptive rather t 
comparative, though arisons are frequently made 
twee m rs of the same grou full account of t 
e e 
external conformation of each group and of its internal structure 
is first given, then follows the description of its reproductive 
methods. The whole is backed by very full tables of the literature 
while the numerous figures which illustrate the text are not only 
well chosen but well executed. The drawings iilustrating habit are, 
for the most part, excellent likenesses. 
turally the mass of fact accumulated in the first volume 
serves as the basis for the more general discussions which fill the 
secund. his opens with a consideration of the basis for the 
systematic arrangement of the Alge, and, in accordance with the 
f 
ily 
differences of their motile cells, a position which the author 
accepts, though not in its extreme form. Such lines of comparison, 
as applied to the simplest organisms, are still at an experimental 
stage, and the consequent groupings are open to further modifica- 
