578 Wm. E. KeUicoU 



partly enclosing Sandusky Bay. Toward the extremity of this 

 point a colony of toads has become established the individuals of 

 which differ in several minor respects from those of the main-land. 

 The colony is fairly isolated geographically and inhabits the lake 

 beach for a distance of about a mile and a half. During the day- 

 time the toads lie buried about two inches below the hot surface of 

 the sand and only a few feet or yards back from the water's edge. 

 Shortly after sunset they uncover and hop down to the water to 

 pick up food carried in by the usually light wash. Food is more 

 than abundant throughout the season and with no particular exer- 

 tion all are able to maintain themselves in an extremely well fed 

 condition. As it becomes fully dark they assemble in this fashion, 

 sometimes just within reach of the water and at the beginning of 

 the season were picked up easily in considerable numbers. Dur- 

 ing the summer almost daily collections were made and toward the 

 end subjects became so rare that ultimately only a dozen or two 

 could be found during an entire week. 



The data therefore were drawn from practically an entire popu- 

 lation occupying a uniform stretch of sandy beach about twenty 

 feet wide and a mile and a half in extent where all were subject to 

 conditions which were remarkably uniform though somewhat 

 unusual for creatures of their kind. And while the total number 

 of individuals measured was not large absolutely, yet it represents 

 nearly lOO per cent of this homogeneous group and consequently 

 the observations are free from errors such as result from the 

 sampling of a larger population. 



2 Methods 



All the toads one or more years old were collected: there is no 

 way of determining their exact age. Since such characters as 

 total weight or weights of viscera are liable to modification by the 

 unusual conditions of confinement, care was taken not only to 

 keep these conditions as nearly normal as possible but also to 

 measure animals only recently removed from their natural sur- 

 roundings. Immediately after collection in the evening the toads 

 were placed in a large sand-box and no more were taken than could 



