Natural History of District of Columhia — McAtee 109 



ACKNOWLEDGMENTS. 



The writer appreciates very much the help of the follow- 

 ing persons in checking up the contents of the preceding 

 three chapters : Messrs. W. E. Maxon, E. A. Preble and E. S. 

 Steele, each of whom read all three; Mrs. Agnes Chase, and 

 Drs. Witmer Stone and E. T. Wherry, who read the first two. 

 Mr. N. H. Darton kindly corrected statements regarding 

 geology and Mr. G. P. VanEseltine checked remarks on the 

 genus, Carex. 



