23 



Harvard Univer.sity, to wIkmu all our inatei'ial lia.s been sent, much of it alive. 

 The work on these collections has all been done and Pi-ofessor Woodworth's 

 paper is nearly ready for publication. 



STUDIES OF PROTOZOA AND ROTIFEKA. 



These minute animal forms of the Station fauna have been very patiently' 

 and thoroughly Avt>rked 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, tliey have been determined as fast as collected. More than 

 tive 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 bj' Mr. Hem- 

 pel and sevei-al others have been identified by Dr. Kofoid in the course of 

 his studies of the plankton since Mr. HempePs work was suspended as a con- 

 sequence of injury to his eyes. Among these later acquisitions was one x>t 

 the most remarkable and important rotifers known to science, a species of 

 the genus Trochosphc>^ra, which is famous in the annals of zoology for the 

 light which it throws upon the zoological relationships of the Rotifera at 

 large. This genus, founded on a species discovered by Professor Semper in 

 1872 in pools in the rice fields of the Phillipiue Islands, 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 189(). 



CHP:MICAL DETERMINATIONS. 



In a thorough going study of the (ecological 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- 

 (juent examinations should be made of the waters at all the typical substa- 

 tions with a view to tracing their chemical history at each throughout 

 the day and under the changing conditions of season, stage of water, and the 

 like. The gaseous contents of the waters ai"e of special interest and import- 

 .auce 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 sanitaiy purposes and even this would have been imprac- 

 ticable if the chemical department of the University of Illiiuiis had not re- 

 sponded generously to my reijuest that such analyses be undertaken. 



Beginning in May, 18!»4, collection-; of water from the river and from 

 various other points in the Station field have been made at regular intervals 

 by Station assistants and shipped to the Chemical Laboratory of the Univer- 

 sity, where they have been examined either by Professor A. W. Palmer or 



