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THE POPULAR SCIENCE MONTHLY. 



always lay at night, and deposit all their eggs in a single nest. As 

 soon as the sun goes down the female sets abont her maternal 

 duties. She wanders over the fields with restless activity until 

 she finds a locality suitable for the formation of the nest. Stub- 

 ble-fields, or those which, having been recently under cultivation, 

 are covered with a thin growth of grass, are preferred. She then 

 begins to scratch up the earth with her hind feet, using first one 



Fig. 3. Old Males fighting. Showing extreme variation in the coloring of the species. 



^From a sketch made at the time.) 



and then the other. After about three hours of patient labor, a 

 small hole about four inches in depth and two inches in diameter, 

 a little wider at the bottom than at the top, has been excavated. 

 An egg is then dropped into the cavity and carefully pushed 

 against the side by the hind foot of the mother ; another is then 

 laid and placed in position as before, until from four to six eggs 

 are ranged side by side in the bottom of the nest. The earth is 

 then carefully scraped back by the hind feet, and finally the 

 grass and leaves are scratched over the opening and pressed down 

 so skillfully that the ground appears as though it had never been 

 broken. By this time it is past midnight It is remarkable that 

 the females do not seem to fear the presence of the observer, but 

 continue their labors, although he may be but a foot or two away. 

 When once started digging the nest they rarely abandon the 

 work. We have observed a tortoise of another species (Nanemys 

 guttata) which dug all night, ami finally completed its nest on the 

 noon of the day following. 



The eggs are covered with a soft white calcareous shell. They 



