MICHIGAN ACADEMY OF SCIENCE. 105 



of the district are one or two small cold trout brooks that empty their waters 

 into the Paw Paw river. 



Starting east of Keeler center and running north of east, is a sand ridge 

 that in some places almost partakes of the character of a dune. In the 

 northwestern part of the region under consideration is found a series of quite 

 precipitous bluffy slopes that border low land to the west. This hill region 

 is remarkable in many ways and will be referred to very often in the follow- 

 ing pages. 



Another feature of topography is the presence of ver}" extensive marshes 

 covering much of the northeast and east part, and but little depressed be- 

 low the surrounding lands. These have largely been imperfectly drained 

 by ditches leading to the Dowagiac Creek. They seem to be, in fact, upper 

 levels of that creek swamp, and seem to locate the uj:)]3er stage of a former 

 extensive lake that filled the whole of the Dowagiac Creek region with an 

 outlet to the southwest. .- The soil is, throughout the higher lands, a gravelly or 

 sandy loam with some admixture of clay, the latter predominating as a sub- 

 soil in the rougher northwest and west portions. The soil of the flat lands 

 and marsh areas is very black from humus and has a large per cent of de- 

 composed sphagnum in its constitution. A number of strips are so sandy 

 as to become practically sterile and useless for agriculture, and so are given 

 over to natural growths. Marl is found in large amount in the lakes as a 

 bottom product, probably of plant origin. 



From an agricultural and horticultural stand-point the soil is not strong, 

 but with clover or fertilizers, well adapted to general crops, particularly beans, 

 and eminently fitted for the growth of small fruits, vineyards and orchards. 

 Probably not much more than 50 per cent is thus utilized, the balance being 

 marsh, forest or waste, or occupied by water bodies. 



Climatically the district enjoys a fairly ec|uable temperature, the range 

 being from about zero in winter to 90 in summer. Rain and snow are well 

 distributed through the months, although August is very apt to be dry. 

 The average rainfall is — inches, and the average temperature — . The 

 prevailing summer winds are southwesterly and westerly, but with many 

 shifts to east. In this connection it is well to record the remarkable climatic 

 ])henomena of Oct. 10-11, 1906. Oct. 10 was a warm day, but cooler by 

 dark, and the late retiring citizen noted a commencing snow fall. The veg- 

 etation was in full green leaf. The morning of the 11th dawned with from 

 8 to 12, inches of snow and a temperature of 2-6 above zero. Forests were 

 broken down by the snow, and peaches were apparently killed root and 

 branch. 



The district may be readily divided into the following more or less well 

 defined plant associations, each of which will be considered in detail: 1st. 

 The wooded Dowagiac swamp with its connected spurs extending up the 

 small or large creeks and ditches joining Dowagiac Creek. 2. The grassy 

 or open bog. 3. The tamarack and huckleberr}' marsh. 4. The ponds and 

 lakes with the larger Silver Creek. 5. The upland oak and hickory lands. 

 6. The beech and maple lands. 7. The isolated pine barrens. 8. The 

 gravelly lake shores. 9. The wooded blufTs bordering some of the lakes. 



I. The Dowagiac swamp is covered with a very heavy growth of Ulmus 

 Americana, Acer saccharinum, Traxinus nigra and Americana, Betula leuta 

 and nigra, Quercus palustris and platanoides, with isolated groves of Pinus 

 strobus. Thuja Platanus and Nyssa. The denser growth has but little under- 

 growth, but in more open and sunny places are many plants peculiar to this 

 region. Among the more noteworthy may be named, Botrychium dissectum, 

 14 



