147 



pressure. The absence of a top to the plant, and its consequent loss of periods of 

 maximum and minimum oxidation, which are the real causes of the variation in 

 the quantity of organic acids in the cell,^ "may be the reason for the failure to 

 produce the expected results. The time of periodicity of root pressure is con- 

 stant in the same genus, but some species may show greater absolute pressure than 

 others. This may be due to accidents in growth, etc. The fact of the periodicity 

 of root pressure seems to be established beyond the possibility of a doubt, and capil- 

 arity and similar phenomena, as suggested by Prof. C. B. Clark " and others, can 

 not account for the facts observed. 



Notes on the Flora of the Lake Region of Northeastern Indiana. 

 By W. W. Chipman. 



A glance at any map of Indiana showing the lakes and marshes will convince 

 one of their special abundance in the north part of the State; and many more 

 will be observed in the northeastern counties than in the northwestern. 



In the Fifteenth Report of the State Geologist of Indiana^, Dr. John M. 

 Coulter divides the State into seven botanical regions, one of which he calls the 

 " Lake Region." Included in this "Lake Region " are the sixteen northernmost 

 counties of the State, with the exception of the very northwestern counties. Lake 

 and Porter. 



I would separate from his Lake Region some of the most northeastern coun- 

 ties, and claim for this territory sufficient peculiar conditions for plant growth to 

 merit its being considered a distinct botanical region, and would call it "The 

 Lake Region of Northeastern Indiana." 



outline of the region. 



A line drawn from the vicinity of Warsaw, Kosciusko County, north along 

 the line of the C, C, C. & St. L. R. R. to its intersection with the northern 

 boundary of the county, and from thence northeast through LaGrange, LaGrange 

 County, to the northern boundary of the State ; and a line drawn from the vicin- 

 ity of Warsaw east along the line of the P., Ft. W. & C. R. R. to its intersection 



^Ward, Proceedings of Royal See, Vol. XLVII, pp. 393-443. 



•^Warbung, Untersuchungen, etc., pp. 77-92. 



'Linnean Soc. Journal. 



'15tb Rep. State Geologist Ind., p. 256. 



