THE GROUND SQUIRRELS OP CALIFORNIA. 



755 



were to be used for traveling expenses of men whose salaries were 

 provided by the public health service. 



As the extensive field operations contemplated could not be carried 

 out quite as per schedule, more time was devoted to conducting experi- 

 ments in control methods. Experimental work covered tests on poisoned 

 grains to a limited extent, but mostly on the noxious gases. From the 

 farmer's viewpoint poisoned grain was sufficient to insure against a 

 heavy crop loss, but it was seen that in order to extend operations over 

 the entire year, the gas methods must be perfected. The officers in 

 charge tried out the numerous gases, as well as machines which had 

 been devised to force the gases throughout the ramifications of the 

 average ground squirrel burrow. There were enough men in the field 

 properly to test the efficacy of the dosages recommended, also the com- 

 parative efficiency of the different mechanical contrivances which 

 insured proper distribution of the gases. The squirrel destructor 

 perfected by one of the officers of the public health service, using carbon 

 disulphid or some of its proprietary mixtures, seemed to work out most 

 satisfactorily, hence was adopted. A few years later the waste-ball 

 method was so systematized as to compete favorably with the destructor 

 both as to economy of labor and costs. 



In addition to experimental work time was taken during a short 

 period for perfecting efficiency records and charts, and computing the 

 economic benefits to be derived from squirrel eradication. Field men 

 were supposed to come up to a certain charted efficiency, which had 

 been computed on the basis of past records. The checking up of the 

 efficiency of operations, the extent of action in the various counties, 

 the exact knowledge obtained by the officers in charge as to proper 

 control portended most favorably for the work. Plague-infected squir- 

 rels were scarce, demonstrations had proven that zones approximately 

 free from squirrels could be produced, co-operation in many cases had 

 been lined up, the centers of population had been protected, the east 

 San Joaquin had been combed for squirrels to such an extent that only 

 one specimen per day was a good record for a hunter, and it was even 

 stated that the five foci of plague 'infection among squirrels would be 

 stamped out by August, 1914. The nature of the disease was not so 

 well understood as to uphold such a prediction, and it has been learned 

 that even to date the spread of bubonic plague among squirrels has not 

 been stamped out. The plague laboratories were perfecting the then 

 known methods of diagnosing bubonic plague and were conducting 

 many controls in determining new features about the disease. 



Without more direct supervision in the field some of the inspectors 

 became automatic report writers, commenting upon their work differ- 

 ently than actual cases proved same to be, hence the supervising inspector 

 and the officer in charge was not always apprised of actual conditions. 



At no time have squirrel-control measures assumed such proportions 

 as did those undertaken by the public health service co-operating with 

 the state board of health, nor is it likely that the annual expenditure 

 of funds under the direction of a single agency will soon approximate 

 the amounts spent by this federal service. In the counties where the 

 work was performed an untold amount of good was accomplished, 

 encountering only the drawback occasioned by a lack of funds with 

 which to follow the work to a successful conclusion. The work has at 



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