TfTE BIOLOGICAL CONQUEST OF Till: Would 27 



to a scientific differoiitiution of specific distribution, AVWor///, Irom 

 .aionoral distribution, Choroloc/!/. 



A Comparison of Two Forests 



Two writers, Victor E. Shclford, the well-known ecologist. and 

 William Beebe, ornithologist and naturalist, have given two widely 

 different pictures, one, an accurate description of a hard-wood forest 

 in Illinois, and the other, a survey of life in a British Guiana jungle 

 forest. 



A typical beech-maple forest, such as Dr. Shelford describes, can 

 be found anywhere in the vicinity of Chicago. A.ssociated with the 

 two dominant trees are ash, elm, walnut, linden, and a wealth of 

 smaller trees and shrubs forming a lower layer under the higher trees. 

 Wild cherry, sassafras, and dogwood are abundant, and in some of 

 the more northern forests, azalea and rhododendron form an inter- 

 mediate growth. The floor of the forest is covered with herbs and 

 flowering plants, large and small, which change with the season. In 

 spring, trilliums, violets, wild geraniums, anemones, phlox, and scores 

 of other plants are in bloom, succeeded in the fall by asters and other 

 composites, in areas having ample light. A relatively large number 

 of plants having spiny or hooked fruits occur, which aid in their 

 accidental distribution by wandering animals. A few large mammals, 

 deer, fox, and hares, are found occa.sionally, though are rarely seen. 

 The woodchuck is perhaps the mo.st numerous of the mammals, and 

 the red, gray, and fox squirrels are not uncommon. Of birds the 

 crested flycatcher, wood pewee, blue jay, scarlet tanager, wood 

 thrush, and red-eyed vireo nest in the lower trees, while the oven-bird 

 conceals its curious architecture on the ground. The wood frog, 

 red-backed salamander, and Pickering's tree frog are found, although 

 not always in evidence, and insects abound, especially those that live 

 on trees, such as borers of various sorts, beetles, millipeds, spiders, 

 and in.sect larvae. Inhabiting the lower layer of the forest are snails, 

 centipedes, sowbugs, and earthworms. This represents, \\\\]\ \aria- 

 tions, a typical association of life in a northern deciduous forest. 



At first sight the jungle forest does not appear to be very difTerent 

 from the northern forest. Both contain large and small trees, the 

 larger ones in the jungle, such as mora and greatheart. towering to a 

 height of two hundred feet or more, but here the likeness stops. 

 There is an almost complete absence of large horizontal branches in 

 the tropical forest, the trunks of trees shooting straight up for si.xty 



