106 ANIMAL COMPETITORS 



overmultiplication ; but the only sort now of 

 importance in that direction is the southern 

 cotton-rat (genus Sigmodon.) The common 

 species (S. hispidum) is typically a denizen of 

 the Atlantic coast from North Carolina to 

 Florida, but its varieties extend the specific 

 range westward to Mexico. The total length 

 is 10-101/4 inches, two-fifths of which belongs 

 to the tail. The color varies a good deal, but 

 in general is a yellowish grizzle above, and 

 ashy to whitish below. 



Their natural habits much resemble those 

 of their neighbors, the pine mice, and like 

 them they have not only surface runways but 

 long galleries and nesting-places under the soil. 

 They may be very numerous without attracting 

 much attention because of this cryptic manner 

 of life, and still more because they rarely come 

 abroad until after dark. There have been 

 times, as in 1889 in western-central Texas, 

 when they swarmed in a regular "plague," and 

 played havoc with the corn-crop. They are 

 especially numerous, always, along the borders 

 of cotton-fields, and Bailey records that in 

 Texas their runways are often fairly lined with 



