1922] WATERMAN—PLANT COMMUNITIES 31 
3- 
gop 
an 
— 
Cowtes, H. C., The physiographic ecology of Chicago and vicinity, a 
study of the origin, development, and classification of plant societies. 
Bot. GAz. 31:73-108; 145-182. 190 
, The causes of vegetative ao. Bor. GAz. 51:161~183. 1911. 
- Moss, C. E., Geographical distribution of vegetation in Somerset. Royal 
Geog. Soc. 1907. 
. Nicuots, G. E., The interpretation and application of certain terms and 
concepts in the ecological classification of plant communities. Plant 
World 20: 305-319; 341-353. 1917. 
, Abstract in printed program of Ecological Society of America for 
Meeting at Toronto, December, 1921 
- TANSLEY, A. G., Types of British vegetation, Cambridge 
ge. Igit. 
, The cliaitiiestion of Pgeaare and the concept of aovcksceien. 
Jour. Ecology 8: 118-149. 19 
WATERMAN, W. G., Sostnae of Crystal Lake Bar region. Ann. Report 
Mich. Acad. Sci. 19:197-208. 1917. 
, Development of root systems under dune conditions. Bor. Gaz. 
68 :40-63, 1919. 
- Wurrrorp, H. N., The genetic development of the forests - Northern 
Michigan. Bor. Gaz. 31: 289-325. Igor. 
