THE 
HEW PHYTOIiOGIST. 
Vol. V., No. 7. July, 1906. 
PROBLEMS IN AOUATIC BIOLOGY, WITH SPECIAL 
REFERENCE TO THE STUDY OF ALGAL PERIODICITY. 
By F. E. Fritsch 
(U niversity College, London). 
fl^HE study of Botany, like that of Zoology, has gradually passed 
| from a purely descriptive and classifying stage to a morpho¬ 
logical or physiological consideration of the diverse organisms and 
their vital functions. For many years the Morphologist and 
Physiologist worked apart and in their segregated seclusion failed 
to recognise how the results which they obtained were really of 
most importance when considered jointly. The Ecologist has been 
the happy means of uniting these two branches of the subject into 
one, the aim of which is to determine the exact relations between 
the plant and its habitat, to show how the special physiological 
processes of the plant are tuned into unison with the conditions of 
the environment and to identify the special structural features of 
the plant with its particular physiological functions. Ecology is not 
a new branch of Botany; it is merely the offspring of the fruitful 
union of Morphology and Physiology. In the last two decades 
many have turned their attention to this aspect of Botany and a 
considerable amount of information has been accumulated. Our 
entire knowledge, however, centres about the terrestrial flora and 
the aquatic Phanerogams, whilst freshwater Algse have received 
little or no attention. The purpose of the present communication 
is to indicate some of the problems with which we are confronted 
at the outset of the study of Algal Biology, and some means 
towards their solution. The field is so large a one and there is such 
a diversity of problems, that much can be done in a fairly limited 
amount of time, although the main points will require years of 
patient observation till an adequate solution is obtained. 
