NOTES AND COMMENT 



H. M. Hall and Joseph Grinnell have published in the Proceedings 

 of the California Academy of Sciences a paper on Life Zone Indicators 

 in California. A brief preliminary discussion is given of some of the 

 conditions which cause nature to depart from the life zone arrangement 

 of organisms in certain localities. Lists of plants, amphibians, rep- 

 tiles, birds, and mammals are given for each of the zones from Lower 

 Sonoran to Arctic-Alpine. The plant lists are confined to perennials 

 and are chiefly made up of trees and shrubs. 



The publication will be of some use to students of plant and animal 

 distribution in California, but it does nothing to give the "life zone 

 concept" a more logical basis than it possessed before. An organism 

 that is supposed to be an indicator of the existence of a particular set 

 of environmental conditions, fluctuating between certain extremes, 

 should presumably be in great part coextensive with these condi- 

 tions. If it is not we are left in the position of wondering what is 

 indicated by the indicator. Even in bringing together a list of organ- 

 isms which are collectively indicative of the existence of a particular 

 gamut of conditions it is difficult to see the force of including species of 

 very restricted range. For example, the authors have listed Pinus 

 radiata, Cupressus macrocarpa and Sequoia gigantea as indicators of the 

 Transition Zone in California. 



The life zone concept is not designed to add anything to our knowl- 

 edge of the causes underlying distributional phenomena, and if every 

 organism growing locally within a zone is to be regarded as an indicator 

 of the zone, the concept will lose its value even as a mere scheme for 

 placing distributional facts in convenient pigeon holes. 



Dr. S. S. Visher has published a report on the Geography of South 

 Dakota, as Bulletin 8 of the South Dakota State Geological and Nat- 

 ural History Survey. The publication covers the geological and physio- 

 graphic features of the state, the climate, the distribution of plant and 

 animal life, and the history of the settlement and present distribution 

 of the population. Some 40 pages of the report are devoted to a dis- 

 cussion of the bio-geography. 



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