Botanical Teaching . 
17 
As the laboratory work was often in advance of the lectures, 
references were usually given to a few papers which were likely to 
prove useful in the course of the investigations. 
The above examples may suffice to illustrate the character and 
scope of the various problems allotted to or chosen by the students. 
The advantages of this method over that which I have previously 
employed were apparent in the much keener interest which was 
taken in the laboratory work; the members of the class were in 
fact engaged in original research, and their attitude was that of 
investigators who have problems to solve which require thoughtful 
treatment and careful technique. They entered fully into the 
spirit of the work and were stimulated to do their best, partly by 
the interest which they derived from the work itself and partly 
from the knowledge that they would be expected to give a clear 
account of their results to the rest of the class, who were 
encouraged to ask questions and offer criticisms during the short 
and informal lecture which the students gave on the completion Of 
each piece of work. 
The practice in speaking and presenting facts, the introduction 
to the methods of research and the stimulus given by the feeling of 
rivalry were, I consider, the most striking advantages of the system. 
A REVISION OF THE CLASSIFICATION OF 
THE GREEN ALG^E 
BY 
F. F. Blackman, 
University Lecturer in Botany, Cambridge. 
AND 
A. G. Tansley, 
Assistant Professor of Botany, University College, London. 
|HE very great advances that have been made within the last 
fifteen years in our knowledge of the structure and relationships 
of the Green Algae, especially the lower forms, have necessitated 
constant revisions of their classification. There is not in English 
any systematic treatment of the affinities of these forms at all in 
