376 NATURAL HISTORY BULLETIN. 



lie found boulders about 40 miles south of what has been 

 considered the limit of drift, and 15 to 60 feet above the Osage! 

 and 2.) that the Missouri could discharge the amount of water 

 necessary to flood the bordering loess-covered highlands. 

 These propositions are here considered separately: 



1. In the first place Professor Wright should not have 

 been "startled" by the occurrence of the boulders in the Osage 

 region, for a similar boulder had previously been found by 

 Professor L. C. Wooster* near Eureka, Kas., at a point still 

 farther south than Tuscumbia, Mo., and farther removed from 

 the recognized drift border. Professor Wright found one 

 boulder at a point "from fifty to sixty feet above highwater 

 mark in the river," and a number of others on a sedimentary 

 terrace "from fifteen to twenty feet above high -water mark, 1 ' 

 and from this he argues that the river must have been dammed 

 sufficiently to account for the water deposition of loess on its 

 bluffs. The weight of this argument will be appreciated, even 

 when allowance is made for the fall to the mouth of the Osage, 

 when it is considered that in Iowa, for example, the hills and 

 bluffs a ong the Missouri rise to a height of 300 to 400 feet 

 above high water, and that even in Missouri they are frequently 

 much more than sixty feet high,"!' and that in all this territory 

 their top - most bulk consists of loess ! 



Both Professor Wright and Miss Owen rejoice that, now 

 that they have found evidence of a barrier so far south, the 

 deposition of loess along the Missouri can easily be explained 

 by the aqueous hypothesis. But they have yet to show how 

 they would account for the deposition of the great, sheet of 

 loess which continues on down the Missouri and Mississippi 

 rivers for several hundred miles, and which at Vicksburg and 

 Natchez rises more than 200 feet above the Mississippi ! 



2. Professor Wright and Miss Owen, and Professor Broad- 

 head who comes to their assistance in a reminiscent letter in 



■-Reported in Science, vol. xii, p. L32, Sept. II, 

 tMiss Owen herself reports, 1. c. Pi. x, some of the loess at St. 

 Joseph 270 feet above the river! 



