23 
4 x 
“Harvard University, to whom all our material has been sent, much of it alive. 
‘The work on these collections has all been done and Professor Woodworth’s 
paper is nearly ready for publication. 
STUDIES OF PROTOZOA AND ROTIFERA. 
These minute animal forms of the Station fauna have been very patiently 
and thoroughly worked out from day to day for nearly two years by Mr. 
Adolph Hempel. As most of them could not be studied to advantage except 
in a living state, they have been determined as fast as collected. More than 
five hundred collections have thus been critically overhauled and annotated 
lists of species and descriptions of new forms have been prepared and either 
published or made ready for publication, in the Bulletin of the State Labora- 
tory of Natural History. 102 species of Rotifera (three new) and 80 species 
of Protozoa (five new) have thus been listed from our situation by Mr. Hem- 
pel and several others have been identified by Dr. Kofoid in the course of 
his studies of the plankton since Mr. Hempel’s work was suspended as a con- 
sequence of injury to his eyes. Among these later acquisitions was one of 
‘the most remarkable and important rotifers known to science, a species of 
the genus Trochosphera, which is famous in the annals of zoology for the 
light which it throws upon the zodlogical relationships of the Rotifera at 
jJarge. This genus, founded on a species discovered by Professor Semper in 
1872 in pools in the riee fields of the Phillipine I slands, is now further repre- 
sented only by collections made at Brisbane, Australia and in the Yangtse- 
Kiang, in China, and by the Illinois River specimens observed by Dr. Kofoid 
‘in the summer of 1896. 
CHEMICAL DETERMINATIONS. 
Ina thorough going study of the cecological system of an aquatic situation, 
the chemical condition of the waters will necessarily be an important element, 
and the Station has consequently 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 be desired that very fre- 
quent examinations should be made of the waters at all the typical substa- 
tions with a view to tracing their chemical histor ‘y at each 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 import- 
ance 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 imprac- 
fieable if the chemical department of the U niversity of Illinois had not re- 
sponded 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 field have been made at regular intervals 
oy Station assistants and shipped to the Chemical Laboratory of the Univer- 
ity, where they have been examined either by Professor A. W. Palmer or 
i 
