284 
determined the prairie in the beginning or fixed its present 
boundaries. 
There are two suggestions that have been made with regard to 
the prairies of the Middle West which deserve more notice, 
though each leaves much to be explained. Alexander Winchell 
in 1864* summed up the opinions of most of his predecessors on 
the subject, indulged in some curious and perhaps not altogether 
essential observations on the vitality of buried seeds, and con- 
F1G.6. About two miles east of Hempstead, looking north. Harbor Hill in 
distance, about 6 miles away. Sept. 27, 1907. 
cluded that the "prairies were treeless because the grasses first 
gained foothold and then maintained it." The same idea has 
recently been expressed more elaborately by.L. Н. Harvey f 
Prof. J. D. Whitney іп 1876f distinguished between the arid 
plains toward the Rocky Mountains and the relatively humid 
prairies near the Mississippi River, showed the inadequacy of 
climatic theories to account for the latter, and pointed out that 
* Am. Jour. Sci. 88: 332-344, 444-445. 
t Bot. Gaz. 46: 86, 297. 1908. 
t Am. Nat. ro: 577—588, 656—667. 
