25 
of the Philippine Islands, is now further represented only by 
collections made at Brisbane, in Australia, and in the Yangtse- 
Kiang, in China, and by the Illinois Biver specimens observed 
by Dr. Kofoid in the summer of 1896. 
CHEMICAL DETERMINATIONS. 
In a thoroughgoing study of the oecological system of an 
aquatic situation, the chemical condition of the waters will 
necessarily be an important element, and the Station has conse¬ 
quently done what was possible to it in its present state to 
institute and encourage chemical studies of the waters from 
which its biological materials are collected. It is much to he 
desired that very frequent examinations should be made of the 
waters at all the typical substations with a view to tracing their 
chemical history at each of them throughout the day and under 
the changing conditions of season, stage of water, and the like. 
The gaseous contents of the waters are of special interest and 
importance to us, since they have probably most to do with the 
welfare of aquatic animals and plants. It has been impossible, 
however, during these first years to provide for more than the 
usual form of chemical examination of water as made for 
sanitary purposes, and even this would have been impracticable 
if the chemical department of the University of Illinois had not 
responded generously to my request that such analyses be 
undertaken. 
Beginning in May, 1894, collections of water from the 
river and from various other points in the Station held have 
been made at regular intervals by Station assistants and shipped 
to the Chemical Laboratory of the University, where they have 
been examined either by Professor A. W. Palmer or by assistants 
working under his direction. Since the beginning of this work 
it has been merged in that of a Chemical Survey of the waters 
of the state established at the University in consequence of 
appropriations made by the state legislature to that end during 
the winter of 1895. One hundred and ninety-three analyses in 
all have now been completed, and a report setting forth the 
comparative results will be published during the current year. 
REPORTS AND PUBLICATIONS. 
The final major product of our Station work must be in the 
