4 



Farmers' Bulletin m7. 



any species of mole occurring elsewhere. The Gibbs mole,^ another 

 west-coast form, is so rare as ordinarily to escape notice. 



The general distribution of the mole seems to depend very largely 

 upon atmospheric humidity and the resulting condition of the soil. 

 Moles are absent altogether from our arid regions, and where the 

 prairies of the Middle West merge gradually into the Plains the 

 animals are found only along water courses. In these regions of 

 deficient rainfall the ground is so dry and hard the greater part of 

 the year as to be wholly unsuited to the existence of earthworms and 

 the various insect larvae upon which the mole depends for subsistence. 

 In the East the mole is most abundant in moist, rich soils along 

 streams, ])articuhuly if these situations are somewhat shaded. In the 



cooler, more uniform 

 climate of the North- 

 west coast region 

 moles are plentiful 

 anywhere in the well- 

 watered valleys. 



DESCRIPTION. 



So seldom is the 

 mole seen, even by 

 those who are famil- 

 iar with its work, 

 that it is often con- 

 fused with other 

 small creatures, par- 

 ticularly the shrew, 

 the vole (or meadow 

 mouse), and the 

 pocket gopher. The 

 cheek pouches of 

 the pocket gopher readily distinguish it from the sightless mole. 

 The mole is not a rodent, and can be readily distinguished from 

 any of these and from the shrew by its short, stout front limbs, 

 ending in broad, rounded hands with palms turned outward; it 

 has a rather elongated body, close plushlike fur, a pointed snout, 

 and a short tail (figs. 2 and 3). Neither external eyes nor ears 

 are ordinarily in evidence. If not totally blind, the common mole 

 of the eastern United States can at best merely distinguish be- 

 tween light and darkness, as what remains of its organs of sight 

 lies wholly beneath the skin. Degeneration of these organs has ap- 



FiG. 1. — Distribution of moles in North America. The 

 Pacific coast area includes the ranges of the Townsend 

 and Gibbs moles (Scapanus and Neurotrichus) ; in the 

 eastern area are the common mole (Scalopus) ^ the star- 

 nosed mole (Condylura) , and the Brewer mole (Para- 

 scalo<ps). 



^ N euro t rich U{< f/ihhsii. 



