6 Mcrriam — Gcoyraph'u- Distrilndiou of Life. 



pines, elk, moose, reindeer, sal.)les, fishers, wolverines, lennnings, 

 musk oxen, and polar l)ears. 



The trogons, saw-l)ills, parrots, cotingas and other hirds of 

 tropical America give place in tnrn to the cardinals, blue gros- 

 beaks, mocking birds, tufted tits, and gnatcatchers of the South- 

 ern States ; the chewink. indigo bird, tanager, bluebird, and rolnn 

 of the Middle and Northern States ; the Canada jays, crossbills, 

 white-throated sparrows, and hawk owls of the northern conifer- 

 ous forests, and the 2)tarmigans, snowy owls, and snowliakes of 

 the Arctic circle. 



Historical Synopsis of Faiinal and Floral Divisions 

 Proposed for North America. 



The recognition of the aljov(;-mentioned facts early led to 

 attempts to divide the surface of the land into faunal and floral 

 regions or zones, and no less than 56 authors have proposed such 

 divisions for North America. Of these, 31 were zoologists and 25 

 botanists. Of the zoologists, 10 aiified to show the distribution 

 of animals in general, 8 of l)irds, 4 of terrestrial mollusks, 3 of 

 mammals, 1 of reptiles and batrachians, and 4 of insects. Of the 

 botanists, 22 aimed to show the distri1)ution of plants in general 

 and 3 of forest trees. 



Of the writers who attempted to indicate the life areas of 

 the New World \)V\ox to 1<S50, 68 percent were botanists, while 

 during the next twenty years (1850-1870), 65 percent were 

 zoologists. This striking oscillation of the biologic pendulum, 

 first toward botany and then toward zoology, may be attri1>uted 

 in jiart at least to the influence of two great minds — Hum- 

 boldt and Agassiz. Humboldt laid the corner-stone of the 

 philosophic study of \A-A\\i geography in 1805. Stimulated Ijy 

 his example and writings, ])otanists led the way and were almost 

 the only occupants of the field until the middle of the present 

 century, when the influence of the elder Agassiz gained the 

 ascendency and the botanists were re})laced Ijy zoologists, wlio 

 have been in the lead ever since. 



The accompanying table shows the various autliors referred to, 

 the dates of the earliest publication of their divisions, the branch 

 of biology on which their conclusion.s were based, and states 

 whether or not their articles were accompanied hy maps. 



