454 D. J. SC0URF1ELD [june 1899 



the very considerable knowledge which we now possess about the 

 organisms constituting the plankton of fresh-water lakes — e.g. their 

 remarkable and often complicated variations in abundance during the 

 year, both collectively and taken species by species, their vertical dis- 

 tribution in regard to the season, to the time of day, to the so-called 

 " Sprungschicht," their occasional seasonal variation of form, their 

 relation to one another and to the other lake forms, notably the fishes, 

 — of all this and much more not one single fact has been contributed 

 by this country ! Who said " Shame " ? 



•REFERENCES .] 



1. Birge, E. A., "Plankton studies on Lake Mendota. 1. The vertical distribution of 



the pelagic Crustacea during July 1894. 2. The Crustacea of the Plankton, July 

 1894-December 1896," Trans. Wisconsin Acad., vol. x. 1895, pp. 421-484, and vol. 

 I xi. 1897, pp. 274-448. 



2. Eigenmann, C. H., " Turkey Lake as a unit of environment and the variation of its 



inhabitants," Proc. Indiana Acad., vol. v. pp. 204-296, 1895. 



3. Forbes, E. B. , "A contribution to a knowledge of North American fresh -water 



Cyclopidae," Bull. Illinois State Lab. Nat. Hist., vol. v. 1897, article ii. 



4. Forbes, S. A., Biennial Report of the Director of the Illinois State Laboratory of 



Natural History, 1895-96 ; Chicago, 1897, 1897-98 ; Urbana, 1898. 



5. Hart, C. A., "On the entomology of the Illinois River and adjacent waters," Bull. 



Illinois State Lab. Nat. Hist., vol. iv. 1895, article vi. 



6. Hempel, A., "Descriptions of new species of Rotifera and Protozoa from the Illinois 



River and adjacent waters," Bull. Illinois State Lab. Nat. Hist., vol. iv. 1896, 

 article x. 



7. Hempel, A., "A list of the Protozoa and Rotifera found in the Illinois River and 



adjacent lakes at Havana, 111.," Bull. Illinois State Lab. Nat. Hist., vol. v. 1898, 

 article vi. 



8. Jennings, H. S., "A list of the Rotatoria of the Great Lakes," Bull. Michigan Fish 



Commission, No. 3, 1894. 



9. Kofoid, C. A., "Plankton studies, I. Methods and apparatus, etc.," Bull. Illinois 



State Lab. Nat. Hist., vol. v. 1897, article i. 



10. Kofoid, C. A., "On some important sources of error in the Plankton method," 



Science, vol. vi. 1897, pp. 829-832. 



11. Kofoid, C. A., "The Fresh-water Biological Stations of America," Amer. Naturalist, 



vol. xxxii. 1898, pp. 391-406. 



12. Kofoid, C. A., "Plankton studies, II. On Pleodorina illinoisensis," Bull. Illinois 



State Lab. Nat. Hist., vol. v. 1898, article v. 



13. Marsh, C. D., "On the Cyclopidae and Calanidae of Lake St. Clair, etc.," Bull. 



Michigan Fish Commission, No. 5, 1895. 



14. Marsh, C. D., "On the limnetic Crustacea of Green Lake," Trans. Wisconsin Acad., 



vol. xi. 1897, pp. 179-224. 



15. Monkhaus, W. J., Proc. Indiana Acad., 1897, pp. 207-231. 



16. Pieters, A. J., "The plants of Lake St. Clair," Bull. Michigan Fish Commission, 



No. 2, 1894. 



17. Reighard, J. E., "A biological examination of Lake St. Clair." With appendices 



on the Protozoa and Mollusca, the Cladocera, the Worms, the Acarina and Insecta, 

 and Suggestions for an Experimental Method of Determining the efficiency of Quanti- 

 tative Nets, Bull. Michigan Fish Commission, No. 4, 1894. 



18. Schacht, F. W., "The North American species of Diaptomus," Bull. Illinois State 



Lab. Nat. Hist., vol. v. 1897, article iii. 



19. Schacht, F. W., "The North American Centropagidae belonging to the Genera 



Osphranticum, Limnnralanus, and Epischura," Bull. Illinois State Lab. Nat. Hist., 

 vol. v. 1897, article iv. 



20. Sharpe, R. "W., "Contribution to a knowledge of the North American Fresh-water 



Ostracoda," Bull. Illinois State Lab. Nat. Hist., vol. iv. article xv. 1897. 



21. Smith, F., "A preliminary account of two new Oligochaeta from Illinois," Bull. 



Illinois State Lab. Nat. Hist., vol. iv. article v. 1895. 



22. Smith, F., "Notes on species of North American Oligochaeta," Bull. Illinois State 



Lab. Nat.^Hist., vol. iv. articles viii. and xiv. 1895 and 1896. 



23. Ward, H. B., "A biological examination of Lake Michigan in the Traverse Bay 



region." "With appendices on the aquatic plants, the Protozoa, the Rotifera, the 

 Turbellaria, and the Mollusca, Bull. Michigan Fish Commission, No. 6, 1896. 



