45 2 



BOTANICAL GAZETTE [june 



marshy land near the old outlet and many of the pine pannes 

 north of the river west of Miller, but has submerged the lower part 

 of a transition oak-pine slope south of the river where a special 

 study of mosses had been begun in 1916-1917. Another similar, 

 but perhaps somewhat more mesophytic, habitat is found near 

 Tremont, Indiana, several miles east of Miller on a slope approxi- 

 mately at the same distance from the lake, and south of a smaller 

 stream, Dune Creek, which also flows nearly west for some distance 

 and here empties into Lake Michigan. This also shows a transi- 

 tion from the conifer to the deciduous type of trees, but contains 

 some more mesophytic species, such as Liriodendron Tulipifera and 

 Acer saccharum, not found at Miller. Mosses are even more 

 abundant here than on the transition slope along the Calumet. 



In addition to the region about Tremont and Miller the dune 

 formations have been studied also at Paul, Pine, Long Lake, and 

 Buffington, all located in Indiana. In all these places the same 

 general conditions are met. Starting at the Lake Michigan beach 

 and going southward may be found, in fairly regular order, first 

 the foredune and cottonwood dune on which there is almost 

 constant shifting of sand, followed by the slightly higher and more 

 nearly established pine dune. This is often succeeded by a transi- 

 tion region of mixed oak and pine which merges into the oak dune 

 proper, so that the oldest of the series and the one farthest from 

 the lake is that of the established mixed oak dune on which 

 Quercus alba and Q. velutina are dominant. These older dunes lie 

 on the border line between the beech-maple climax region of the 

 eastern United States and the oak-hickory climax which seems to 

 be typical near the Mississippi River. For this reason it is some- 

 what difficult to determine whether these oak forests belong to the 

 latter climax type, or are subclimax associations which will in 

 time develop into the beech-maple type (3). 



South of the dune complex just mentioned is another inter- 

 esting type of topography very completely described by Shelford 

 (10). This is a low swampy area made up of long shallow ponds 

 or lagoons, nearly 100 in number, separated by ridges and extend- 

 ing almost parallel to the present lake shore. These ridges were 

 formed by the building up of barrier beaches along the former 



