MAMMALIA. 



3*3 



FlG. 338. Star-nosed mole (Condylura cristata) ; 

 a, jaws ; 6, end of nose. 



obtaining food. They are found near streams and moist 

 spots. The common mole (Scalops aquaticus, Linn.) (Fig. 

 339) leaves its 

 traces in up- 

 turned ridges in 

 every field of 

 the Eastern 

 States. They 

 attain a length 

 of five inches. 

 The fore -feet 

 are greatly de- 

 veloped for 

 digging ; their 

 eyes are com- 

 paratively use- 

 less, being ex- 

 tremely small,* 



giving rise to the impression that they are eyeless. Their 

 nests are underground, and their principal food earth- 

 worms. 



Allied are the Solenodon of Hayti and the Tanrec of 

 Madagascar. 



VALUE. Fur, and as insect-destroyers. A single mole is estimated 

 to eat 20,000 insects in a year. One has been known to devour 432 

 maggots and 250 grubs in four days ; another ate 872 maggots and 540 

 grubs in twelve days. In another instance two moles in nine days de- 

 voured 341 grubs, 193 earth-worms, 25 caterpillars, and a mouse, its 

 bones and skin. 



* The eyes are deeply imbedded, but are perfect, the lens consist- 

 ing of a very small number of minute and little altered embryonic 

 cells. The retina is more simple than generally seen in other ver- 

 tebrates. In the embryo mole both eyes are connected with the 

 brain by optic nerves, but in adults the optic nerve has degenerated, 

 sometimes one and again both, so that, though the image may be 

 possibly formed in the eye, it is with difficulty communicated to the 

 brain. 



