THE GROUND SQUIRRELS OF CALIFORNIA. 



743 



Chlorine has been tried out by Horticultural Commissioner A. A. 

 Brock with favorable results, and with gas impounded under pressure 

 in cylinders with a calibrated apparatus of some sort for measuring 

 quantity, a future for this method seems promising. The cost will be 

 very low, perhaps only a fraction of a cent. 



Attention has been called to a means of combating meadow mice 

 with calcium carbide and water to form acetylene gas, with good results. 



It has been the policy of the Rodent Control Division of the State 

 Commission of Horticulture to "try out" various commercial and pro- 

 prietary products and compounds exploited as being the most effective 

 on the market for controlling noxious rodent pests. This is done merely 

 to satisfy the personnel of the division that the product has some 

 grounds for being on the market, but at no time have written state- 

 ments been given out vouching for the superiority of one preparation 

 over another, unless it was felt that by so doing the standard of all 

 offered for sale could be bettered; this then affected not one but all. 

 If there are not available enough elemental or original ingredients for 

 a landowner to prepare a suitable rodent exterminator himself that is 

 a different matter, but in these days this does not chance to be the case. 

 If a manufactured article must have the endorsement of public officials 

 to further its sales, the inference generally drawn is that it can not 

 stand on its own merits. If demonstrations are in order, they should 

 be made to the people for whose benefit they have been prepared and 

 to whom they are offered for sale. It is believed that strict adherence 

 to such a policy will obviate any criticism involving discrimination 

 against any particular product. 



Questions have been asked of all field men combating squirrels if some 

 disease could not be isolated which when inoculated into ground squir- 

 rels would spread rapidly enough to insure a final epidemic. It must 

 be admitted that nothing is known which will bring about such results. 

 However, at one time such a disease was supposed to have been pro- 

 duced by the so-called Pasteur Rodent Virus. This preparation was a 

 culture of a disease germ reputed to have been isolated at the Pasteur 

 Institute at Paris. It had been exploited in Europe, whence it came 

 with recommendations, and in the eastern United States, before being 

 brought to the Pacific coast in 1896. It seems, however, that rather too 

 extravagant claims were made for this particular virus before it was 

 given a test on the California ground squirrel. The method of appli- 

 cation called for equivalent amounts of the liquid virus and boiled 

 water to which a little salt had been added; two or three small pieces 

 of bread, which had been dipped into this combination were "set" at 

 each burrow. The contagion was intended to spread, with fatalities 

 among ground squirrels for miles throughout the locality. Reports of 

 success came from here and there, but the results of the use of this 

 product were at no time such as to cause a heavy demand from dealers. 

 It was harmless to all domestic stock, excepting some effect on poultry, 

 and this called for caution when used about yards and barns. A 

 veterinary in Fresno County did some good work and one report from 

 Santa Barbara gave a boost. It was tried on rabbits, using raisins and 

 corn for bait. No report of any particular moment ever came of this. 

 As with all such preparations, the dependence upon the possibility of 

 close contact of individuals of the species proved to be a useless one, 



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