I6O ARTHUR G. VESTAL. 



species. The habitats in which few or no grasshoppers are found 

 are those in which the soil is not suitable for egg-laying. 



In many animals the breeding period occupies a rather small 

 part of the season of activity, and the adult animal may spend 

 but a small proporlion of its active life in the breeding stratum or 

 habitat. The habitat in which the species occurs most regularly 

 and in the greatest numbers is the habitat in which the species is 

 of greatest influence. It is the most important habitat of the 

 species so far as plants and other animals are concerned. In 

 associational studies, in which emphasis is laid upon relations 

 between organisms, this habitat is most important. The animal 

 may feed in several habitats, but principally in the habitat in 

 which it is most frequent and abundant. The feeding activities, 

 though of secondary importance (usually) in determining the 

 presence of an animal in a particular habitat and a pardcular 

 region, are of primary importance in relation to the communities 

 of plants and animals of which the species becomes a member. 

 In the study of all the habitats within a given region, emphasis 

 would be placed on the habitat in which the species is most 

 frequent and most abundant. The success of the species in the 

 various habitats, as indicated by relative numbers, is a measure 

 of the degree of correspondence between the environmental 

 conditions actually furnished within the area of the habitat, and 

 those required by the animal. The habitat in which the species 

 is found most regularly and in the greatest numbers is the habitat 

 in that region which most closely approximates the optimum 

 environment for the species. 



The Different Activities in Climatic and in Local Habitats. It 

 so happens, in probably the majority of the grasshopper species 

 of the Douglas Lake region, that the feeding habitats and the 

 breeding habitats coincide more or less perfectly. In insects of 

 incomplete metamorphosis, as Orthoptera, the possibility for the 

 immature animals to correspond in mode of life rather closely 

 to the adults is much greater than in insects in which changes 

 from larva to adult are more radical. Grasshopper nymphs 

 feed and hop about as do the adults. They cannot fly, but as 

 flying more commonly does not take the animal into another 

 habitat, this difference is of minor importance. Where the 



