COMMUNITIES 37 



munities based upon minor differences in habitats, and formations based 

 upon larger major differences in habitats. 



We give the communities of different orders below with taxonomic 

 divisions of corresponding magnitude opposite for comparison. With 

 the exception of the first, these taxonomic groupings do not bear the 

 slightest relation to the ecological groupings, but are added to indicate 

 magnitude. 



Ecological Groups Taxonomic Groups 



(Mas) mores Form (forms) (species) 



Consocies Genus 



Stratum or story Family 



Association or society Order 



Formation Class 



Extensive formation Phylum 



(Aquatic and terrestrial) (Vertebrates and invertebrates) 



Mores, in the technical sense in which the term is used here, are 

 groups of organisms in full agreement as to physiological life histories 

 as shown by the details of habitat preference, time of reproduction, 

 reactions to physical factors of the environment, etc. The organisms 

 constituting a mores usually belong to a single species but may include 

 more than one species as specificities of behavior are not significant (13). 



Consocies are groups of mores usually dominated by one or two of the 

 mores concerned and in agreement as to the main features of habitat 

 preference, reaction to physical factors, time of reproduction, etc. 

 Example: the prairie aphid consocies. The aphids dominate a group 

 of organisms which for the most part prey upon them, as, for instance, 

 certain species of lacewing, lady beetles, syrphus-flies, etc. (13). 



Strata are groups of consocies occupying the recognizable vertical 

 divisions of a uniform area. Strata are in agreement as to material for 

 abode and general physical conditions but in less detail than the consocies 

 which constitute them (13). 



For example, a forest-animal community is clearly divisible into the 

 subterranean-ground stratum, field stratum (zone of the tops of the 

 herbaceous vegetation), the shrub stratum (zone of the tops of the 

 dominant shrubs), the lower tree stratum (zone of the shaded branches 

 of the trees), and the upper tree stratum. A given animal is classified 

 primarily with the stratum in which it breeds, as being most important 

 to it, and secondarily with the stratum in which it feeds, etc., as in many 

 cases most important to other animals. The migration of animals from 



