60 ILLINOIS BIOLOGICAL MONOGRAPHS [410 



LIFE HISTORIES OF POCKET GOPHER ANOPLOCEPHALIDS 



Throughout the present studies attention has been given to the 

 problem of the life-histories of the cestodes of the pocket gopher. This 

 problem has been attacked in three ways: by experimental feeding, by 

 examination of suspected hosts for cysticercoids, and by observations on 

 the habits of the gopher. Either the first or second method, or both, 

 have been tried out on all the parasites and commensals of the gopher 

 which I have been able to find, with only negative results as yet; it is 

 my intention to keep steadily at this quest whenever opportunity offers. 

 Observations on the habits of the gopher however have yielded infor- 

 mation which may prove of decided value in the quest of the intermedi- 

 ate hosts of the Anoplocephalidae, and this information is given here 

 in the hope that the facts may be of assistance to other workers who 

 are giving attention to this subject. In order to make the matter clear 

 a brief statement is necessary concerning the habits of the gopher. 



I have found Geomys personatus always in infertile, sandy ground. 

 Geomys breviceps I have caught at various points in Texas and Okla- 

 homa; but nowhere except at Norman, Oklahoma, have I caught them 

 in anything except upland regions in very sandy soil. At Norman, 

 gophers were taken along a stream valley in soil that is of a sandy na- 

 ture but fertile and moist. Geomys bursarius I have found to range 

 over about every conceivable locality. They thrive on the borders of 

 swamps, on hilltops, on open plains, in heavy pine forests, in wind- 

 blown sand, and in heavy clay soil, whether uplands or lowlands. 



Wherever he occurs, the gopher leads a life wholly apart from his 

 fellows except at the mating season. His tunnel is seldom as much as 

 50 meters long. This tunnel is practically the gopher's world except 

 during the mating seasom In the evening he may come to the top of 

 the ground for a few moments; but he does not wander more than a 

 few feet from the mouth of the burrow. In regard to the occurrence 

 of all the species of Anoplocephalidae found infesting the gopher, one 

 rule has proved to be invariable : they occur only in gophers inhabiting 

 rich soils, preferably clay soils, but occasionally in sand when it is 

 mixed with humus and is of a swampy nature. To this rule I have 

 found not a single exception. Apparently not all regions of fertile soil 

 are infected, and lowlands in the main are most heavily infected. 

 Swampy places have been found to yield the best of all. 



A specific instance is illuminating. At Brainerd, Minnesota, fifteen 

 gophers were caught in the sandhills; on examination one cestode was 

 found which belonged in the genus Hymenolepis. The traps were then 

 moved to Bean Flat, 200 meters away. Bean Flat is a low, almost 



