248 



Nichols: The vegetation of Connecticut 



No plants can yet get a foothold in such a place, unless it be a few 

 species that may be able to make their appearance between 

 periods of landslide action; among these plants annuals particu- 

 larly predominate. The perennials that may be found in such 

 places are almost entirely plants which have slid down the bank. 

 Ravines of a similar type may be seen in many places inland, and 

 wherever found the poverty of vegetation on the slopes is the most 

 striking character. 



Fig. 4. An embryonic ravine in a clay \Aufi along the western shore of Lake 

 Michigan. Vegetation entirely absent on the unstable clay slopes, except for shrubs 

 and grasses which have slid down from the top. (After Cowles, Physiographic 

 ecology of Chicago and vicinity; photograph furnished by H. C. Cowles.) 



"As the ravine extends itself inland the conditions outlined 

 above may be always seen about its head, but toward the mouth of 

 the ravine the slopes are less precipitous. Torrents cut down the 

 bed of the ravine until a depth is reached approaching the water 

 level at its mouth. From this time on the slopes become reduced 

 and the ravine widens more than it deepens, by reason of lateral 

 cutting, landslide action, and side gullies. After a time a sufficient 

 stability is reached to permit a considerable growth of vegetation. 



