An indication of the comparative mildness of tJie Mt. 

 Desert climate, in spite of its arctic flora, is to be found in a 

 group of Japanese pines growing at one of the gateways 

 north of the village of Bar Harbor, a tree so sensitive to 

 cold that it is killed at the latitude of New York, which yet 

 has lived on this island for twenty years without protection 

 in winter. 



It appears that the same interesting distribiitional rela- 

 tionships are found among the insects of the island. Dr. 

 C. W. Johnson of Boston collected in Witch Hole Pond a cer- 

 tain insect which had hitherto been recorded only from ex- 

 treme northern Europe and Alaska; and yet he has found 

 many southern forms. He has also discovered on the island 

 a number of species hitherto unknown to science. 



Scientists all over America are urging the preservation 

 of natural areas for scientific study. In research on distri- 

 bution, on the influence of environment upon pfants and ani- 

 mals, and on adaptation, it is essential to have areas on 

 which the flora and fauna can be found undisturbed by out- 

 side agencies. The creation of the Lafayette National park 

 on an island of such great interest as Mount Desert Island 

 is, therefore, of the utmost importance to science. 



Little is known for sure yet of the causes of this import- 

 ant distribution. 



These causes are not only interesting in themselves, but 

 should help solve ecological problems. 

 Many of the factors to be considered: 



1. Northward migration after retreat of glaciers. Land 

 connection with coastal plain to account for pitch pine and 

 C. P. species. 



2. Coolness of Arctic current probably a factor in Arc- 

 tic species along shore. 



3. Uniformity of ocean climate for parts of island in 

 preventing extreme changes. 



4. Variety of habitats due to mountains. Exposure and 

 shelter, moisture and dryness; intense isolation vs. mountain 

 shadows; steep vs. gentle slopes; bare rock vs. soil. 



5. Result must be different climate in different places. 

 Different temperature, moisture, light and evaporation. 



6. Soil. Certain amount of variety. Mostly glacial 

 and decomposed granite. Mostly rather sandy and gravelly, 

 but some heavy clays, notably a blue marl. Most soils slight- 

 ly acid, but some neutral. Surface humus of forest strongly 

 acid. 



101 



