84 



The accumulations of material and notes were already sufficiently large for 

 group studies at the beginninp^ of the two j'ear period covered by this report. 

 Every opportunity has been taken to make desirable additions to them, and 

 they now stand as a superb basis for the study of any gi'oup of aquatic forms. 

 The material is all arranged by order.;,, and consists of about 4,250 vials and 

 bottles of specimens. 



There are now in various stages of preparation four papers, mainly on the 

 entomology of the biological station field, one each on the Odonata, the 

 Ephemerida, the fresh-water Mollusca and the aquatic Coleoptera. The order 

 of procedure which I have endeavored to pursue in the preparation of these 

 papers, and which seems to lead to the most satisfactory and accurate results, 

 is as follows: First, the collection of a large quantity of material and data 

 under the greatest possible variety of conditions as to locality, surroundings, 

 stage of water, season and time of day; then the careful study of these, in 

 connection with the literature, and the making of copious notes and sketches 

 preliminary to the preparation of manuscript, all evident deficiencies either 

 in material or data being carefully noted down; ne.xt, a return to the field at 

 times and places indicated by the previous collections for the special purpose 

 of supplying, as far as possible, these deficiencies, and finally, after further 

 study of the literature, the writing of the manuscript. 



In the preparation of the paper on the Odonata I have had the valued as- 

 sistance of Prof. J. G. Needham and Mr. C. C. Adams, who have furnished 

 the systematic work on the nymphs and adults respectively, while it has been 

 my part to discuss the biology and oecology of the group and its species and 

 to combine the several manuscripts into a single papei* — now nearly ready for' 

 the press. Under Mr. Adams' supervision the State Laboratory Artist. Miss 

 Hart, has prepared a valuable series of 134 drawings illustrating the abdomi- 

 nal structures of nearly all our Illinois species, and a series of general draw- 

 ings of the nymphs and their distinguishing structures is well under way. 



For the ai'ticle on Ephemerida, the station collections and notes have all 

 been examined and the results are nearly ready to be put in manuscript form. 

 It would add greatly to the usefulness of the paper, however, if a study of 

 the large series of nymphs of this order in the general collections of the State 

 Laboratory could be made before the article is completed. 



Much time and labor have been spent on the 3[ollusca in the endeavor to place 

 the study of this group on a truly scienrific basis. Not merely the shell, but all 

 parts of the animal were studied, full use being made of the unusual facilities at 

 the station for work o'^ this kind. The univalves of the station collection have 

 been determined by Mr. H. A. Pilsbry, of the University of Pennsylvania, 

 and the Splucrium and Pisidium by Dr. V. Sterki. More time could profitably 

 be spent on the biology of the Unionidce, but otherwise the notes ai'e ready to 

 go into manuscript form. 



The collections of water beetles have been exhaustively studied and deter- 

 mined, but the sj'stematic examination of the immature stages has not yet 

 been reached. 



Respectfully submitted, 



C. A. Hart,. 



Entomolog^icol Assistant. 



REPORT ON THE SUMMER SCHOOL OP 1898. 



To the Director of the Lnhoratonj . 



Sir: — Of the fifteeu persons in regular attendance at the summer school 

 twelve were either teachers or preparing to teach, in our public schools. Five 

 of them had received training in the laboratories of the University of Illinois, 

 but nearly all of them were without any considerable experience in fieldwork 

 or in the methods of collecting and preserving aquatic oi'ganisms. On this 

 account especial prominence was given to tri-weekly excursions for collecting 

 and field obseiwation, and these furnished probal)ly the mo.st important ele- 

 ments in the work of the session. With the steam launch, row boats, and 



