190 Footprints 



birds have not the same size or shape of foot. 

 A water-snake came up over the mud and 

 left a line of marks upon the sand that could 

 not be recognized as that of any animal, ex- 

 cept it might be a faint resemblance to the trail 

 of a mussel. I chased a dozen crayfish over 

 a mud flat, and their backward and sidewise 

 leapings caused an old gunner to say there 

 had been plover about. A blue-winged teal 

 made a long double line of dents in the sand 

 before it rose clear of the beach, and these 

 were very like many a footprint I had pre- 

 viously seen. What, then, must we think of 

 the fossil footprints of which so much has 

 been written ? As different species, a long 

 series of these impressions in the rock have 

 been described and given high-sounding titles. 

 I am not entitled to an opinion, but have 

 doubts, nevertheless, of the wisdom of con- 

 sidering every slightly different form as made 

 by a different creature. I have given my 

 reasons, and will only add another instance, 

 one of greater significance than all as bear- 

 ing upon the question. I startled a slum- 

 bering jumping-mouse last summer and it 

 bounded across the smooth sand bared by the 

 outgoing tide. Its track then was one made 



