90 KANSAS UNIVERSITY SCIENCE BULLETIN, 



streams in winter and construct their burrows in the spring 

 for the purpose of rearing their young and escaping the sum- 

 mer droughts. He says : "I found one burrow which, on my 

 first visit, was but six inches deep, and later had been pro- 

 jected to a depth of at least twice as great, and the inhabitant 

 was an old female." He concludes that while the marsh is 

 still covered with water after the winter has passed impregna- 

 tion takes place and the burrows are immediately begun. At 

 first the direction is oblique, and so long as the mouth is cov- 

 ered with water this is satisfactory, but upon .the receding of 

 the water a perpendicular burrow becomes more economical 

 and this direction is maintained with more or less regularity, 

 the perpendicular opening to the surface representing a shorter 

 route for conveying the mud from the deeper excavation, the 

 height of the mound over the vertical shaft depending upon the 

 depth of the latter. 



"About the middle of May the eggs hatch, and for a time 

 the young cling to the mother. . . . After hatching, they 

 must grow rapidly, and soen the burrow will be too small for 

 them to live in, and they must migrate." 



Tarr considered that the chimney was not "a necessary part 

 of the nest," but only the mud brought up in digging. He 

 carried away several chimneys, and no attempt was made to 

 replace them but in one case, where, after removing the chim- 

 ney, he partially filled the hole with mud, there was a simple 

 half-rim of dried mud when the place was again visited, indi- 

 cating that the burrow had been cleared soon after the first 

 visit. 



He says: "There is seldom more than a pint of water in 

 each hole, and this is muddy and hardly suitable to sustain 

 life. . . . How these animals can live for months in the 

 muddy, impure water is to me a puzzle. They are very slug- 

 gish, possessing none of the quick motions of their allied C. 

 bartonii, for, when taken out and placed either in water or on 

 the ground, they move slowly. The power of throwing off 

 their claws when grasped is often exercised." 



Tarr leaves as a question the method of securing food. Evi- 

 dently they do not "tunnel" for roots. "Food must be se- 

 cured at night or when the sun was not shining brightly. In 

 the spring and fall the tender stalks of meadow grasses would 



