57 



Brooklyn Botanic Garden and the New York Botanical Garden. 

 The beautiful hemlock grove in the Bronx Garden gave the 

 visitors their first glimpse of the climax forest of the east. 



Except for a stop at Niagara Falls the journey to Chicago was 

 uneventful. Chicago lies in the transition area between the 

 forested region of the east and the prairie region of the middle 

 west, and the distribution here of forest and prairie is influenced 

 largely by edaphic factors. On the uplands forests occupy the 

 glacial moraines and the beaches of the former Lake Chicago; 

 the rest of the country is grassland.* During the week here 

 visits were made to prairies and oak-hickory (Quercus sp., 

 Hicoria sp.) forests near the city, to clay bluffs and ravines 

 along the lake north of the city, to a tamarack {Larix laricina) 

 swamp in northern Indiana, and to a magnificent tract of virgin 

 beech-maple {Fagus grandifoUa, Acer Saccharum) forest in south- 

 ern Michigan — a forest much like those of southern New England 

 in its general aspect, but of a more mesophytic type than those 

 west of Lake Michigan. The real drawing card in this region, 

 however, is the sand-dunes which fringe almost uninterruptedly 

 the eastern margin of Lake Michigan, continuing around the 

 southern end of the lake and along the western shore as far as 

 Chicago. Two entire days were devoted to the study of this 

 fascinating area, whose vegetation has been so graphically 

 portrayed by Cowles.f 



The excursionists left Chicago on the evening of August 8, 

 and arrived in Lincoln, Nebraska, on the following morning. 

 The country about Lincoln is one of rolling prairies with tortuous 

 lines of trees fringing the streams. These stream forests, best 

 developed on the flood plains, represent the westernmost exten- 

 sions of the deciduous forests of the east. Once the eastern 

 botanist, westward-bound, has left these behind, he has severed, 

 so to speak, the last familiar tie. The prairies themselves in their 

 midsummer aspect are depressing. A hasty survey of the region 



* For further discussion see Cowles, H. C. The physiographic ecology of 

 Chicago and vicinity. Bot. Gaz. 31: 78-108, 145-182. 1901. 



t Cowles, H. C. The ecological relations of the vegetation on the sand dunes 

 of Lake Michigan. Bot. Gaz. 27: 95-117; 167-202, 281-308; 361-391. fig. 1-162. 

 1899. 



