500 



THE NATIONAL GEOGRAPHIC MAGAZINE 



Photograph by Howard Taylor JMiddlcton 



YOUNG RED SQUIRRELS AND TIIEIR NEST 



These cute little chaps were found cozily at rest in their nest in 

 a pine. They were routed out, however, long enough to have their 

 portraits taken. An effort was made to include the mother, but 

 without success (see page SS6). 



of their food here, resulting in a large increase 

 in the rodent population, but that it was then 

 becoming scarce through a failure of rain to 

 renew the seed harvest. The invariable out- 

 come in such cases is for the small rodents de- 

 pendent on seeds and fruits to be reduced by 

 famine until they become rare, where previ- 

 ously they existed in great numl)crs. This is 

 one of Nature's processes whereby the danger 

 of the overwhelming increase of any species is 

 automatically prevented. 



THE POCKET GOPHERS (Geomys bur- 

 sarius and its relatives) 



{Por illustration, see page 515) 



With the exception of the moles no other ex- 

 tensive group of .\merican land mammals is so 



highly specialized for a 

 peculiarly restricted mode 

 of life as the pocket go- 

 phers. They form a 

 strongly marked family, 

 the Geomyidse, which in- 

 cludes various genera and 

 many species, all very 

 similar in external form, 

 but varying from the 

 size of a large mouse to 

 a massively formed ani- 

 mal equalling a large 

 house rat in weight. 



Without exception they 

 are powerfully built for 

 their size, the head and 

 front half of the body 

 being extraordinarily 

 muscled to meet the de- 

 mands of their mode of 

 life. The broad blunt 

 head is joined almost di- 

 rectly on the body. The 

 eyes are small and have 

 the restricted vision to 

 be expected from animals 

 living underground. The 

 ears are reduced to little 

 fleshy rims about the 

 openings, and the short 

 naked tail is provided 

 with nerves, which ren- 

 der it useful as an organ 

 (if touch. 



The front teeth are 

 broad, cutting chisels, 

 and on each side of the 

 mouth is a large pocket 

 in the skin used for gath- 

 ering and carrying food. 

 On the front feet are 

 long claws, which, when 

 not lieing used to dig or 

 handle earth, are doubled 

 under, against the soles 

 of the feet, so that the 

 gopher walks on the back 

 of them much as the ant- 

 eater walks on its folded 

 claws. 

 Peculiar to North America, pocket gophers 

 occupy a great area extending from Illinois, 

 Florida, and the Gulf of Mexico to the Pacific 

 coast, and from the plains of the Saskatchewan, 

 in Canada, southward to Panama. Their ver- 

 tical range within these limits extends from sea 

 level to timber-line, at above 13,000 feet on 

 some of tiie higli volcanoes of Mexico. The 

 family attains its greatest development in that 

 wonderful region of plains and volcanoes lying 

 about the southern end of the Mexican table- 

 land. 



In the United States these animals are best 

 known as "gophers," but in the range they 

 occupy in the Southeastern States they_ are 

 called "salamanders" and in Mexico are widely 

 known as "tuzas." As a rule they frequent 

 treeless areas, but are found also in many 



