172 ARTHUR G. VESTAL. 



glacialis variegata has not been taken in the beech-maple forest, 

 but probably occurs there. It differs from the other grass- 

 hoppers of the region in being of the shrub stratum, rather than 

 of the ground or herbaceous strata. 



The species in the table are arranged approximately in the 

 order of succession of the associations in which they occur. 

 Melanoplus atlanis, being more generally distributed, can hardly 

 be assigned to a particular place in the series, and is placed at the 

 bottom accordingly. It is most abundant in ruderal grassland, 

 and is not at all common in forest. 



A parallel development of vegetation in sand is seen in a region 

 in central Illinois. The herbaceous vegetation is sand prairie, 

 is very open in the initial stages, and is replaced by xerophytic 

 oak forest before a closed grassland is reached. The habitat- 

 relations of the various grasshopper species are discussed by 

 Hart ('07). A number of the species of the Douglas Lake region 

 are here represented in habitats occupying equivalent stages in 

 the successional series. 



The initial stages of herbaceous growth, characterized by a 

 large proportion of bare surface, are accompanied by active, 

 very motile grasshoppers which rest normally on the surface and 

 which lay eggs in soil of loose texture. With the closing of the 

 herbaceous growth grasshoppers of this habit gradually decrease 

 in numbers, giving way to species which rest part of the time 

 upon the vegetation, which are less motile, and which lay eggs 

 in the less sterile types of soil of such situations. In sand regions 

 of the forest climate, usually, forest invasion occurs before the 

 herbaceous growth becomes closed. The ground conditions 

 remain those of grassland until the forest approaches the closed 

 stage, when the grasshoppers of open grassland are abruptly 

 replaced by forest grasshoppers, which are less motile, usually 

 flightless. They are fewer in species and individuals than grass- 

 land members of the group, in part because of the fact that in 

 advanced forest stages, in which the ground is almost entirely 

 covered with dead leaves, the soil is generally inaccessible for 

 egg-laying, and oviposition takes place typically in wood. 



