Alfalfa in Kansas. 357 



dog or a spermophile digs a burrow very much like that of his neighbor, 

 but it must be borne in mind that these animals are constructing homes, 

 not extending passageways in search of food. The gopher follows his 

 own sweet will in mining. Here a chance for easier digging turns him 

 aside; there a promising lead of succulent roots entices him the other 

 way. Heading everywhere in general and nowhere in particular, he 

 may in the course of a year explore the length and breadth of a field of 

 many acres. At irregular intervals he excavates a short lateral obliquely 

 upward to the surface of the ground. Through these the loosened dirt 

 is carried and thrust out in heaps. The presence of a gopher is thus 

 easily detected by the lines of mounds, varying in size from a hatful to 

 one or even several bushels of dirt. A study of a fresh mound reveals 

 the plan of construction. The dirt is carried out of the opening and dis- 

 tributed radially, very much as miners dispose of the useless shale from 

 a coal pit. Usually the dump extends only part way around the opening, 

 but sometimes the mound has the shape of a cone with a crater at the 

 top. Where surface vegetation hinders the work the piles of dirt are 

 more irregular. 



MOLE RUNWAYS. The ridges and mounds of earth thrown up by 

 moles are often incorrectly supposed to be the work of gophers. A 

 little careful scrutiny will soon reveal the difference. The gopher piles 

 up the dirt on the surface of the ground, building a mound by the addi- 

 tion of load after load on top of that already deposited. A mole simply 

 heaves up the dirt from beneath, forming piles which show radiating 

 cracks. Associated with these piles are the surface ridges made by the 

 animal when ranging in search of food. The feeding runways of the 

 gopher never show in surface ridges. 



BREEDING. As might be expected of animals living in such compara- 

 tive security, the pocket gopher is not a very prolific breeder. It cer- 

 tainly rears but one litter a year in this locality, for I have examined 

 scores of specimens in all months of the year and have found the em- 

 bryos only in late winter and early spring. The number of young in a 

 litter varies from three to six, and averages a little more than four. 

 Very rarely only two embryos are found in the uteri. 



NATURAL FOOD. The natural food of the pocket gopher consists of 

 the fleshy roots and underground stems of various plants growing 

 wild on the prairies. To this bill of fare he adds occasionally a 

 small quantity of succulent vegetation drawn down into his burrow 

 from the surface at points where exits are dug for removing earth. 

 When foraging thus above ground he loses no time in cramming supplies 

 into his cheek pockets and hurrying below to eat the stuff at his leisure. 

 The underground stems and roots he encounters in extending his bur- 

 rows are cut into short pieces of convenient length to carry, provided he 

 does not care to dine upon the spot. The sections thus made are com- 

 monly an inch or two in length, sometimes shorter, but I have found 

 stores of alfalfa roots in which dozens of the pieces ranged from four 

 to eight inches long. These, of course, the animal must carry or drag 

 to the storeroom without the aid of his pockets. The same is necessarily 



