Formula for poisoned bait.—­Dissolve 1 ounce of strychnine sulphate in 1-1/2 pints of boiling water.  Add 1 heaping tablespoonful of gloss starch, previously mixed with a little cold water, and boil until a clear paste is formed.  Add 1 ounce of baking soda and stir to a creamy mass.  Add 1/2 ounce of glycerine and 1/4 pint of corn sirup and stir thoroughly.  Pour over 16 quarts of rolled barley and mix well until every grain is evenly coated.  Allow to dry before using.

     In bushel quantities use as above directed, 2 ounces of strychnine,
     2 ounces of soda, 1 ounce of glycerin, 1-1/4 ounces of starch,
     1-1/2 quarts of boiling water, and 5/8 pint of corn sirup.

     Scatter poison, when the natural food of the kangaroo rat is
     scarce, on clean hard places near the holes, 1 quart to 50 holes.

If powdered strychnine alkaloid is used, prepare the hot starch paste first.  Then sift strychnine and baking soda, previously thoroughly mixed, into the hot starch paste and stir to a creamy mass.  Proceed as in the above directions with sirup, glycerin, etc.

     Use this poison within five days after mixing or retain in
     air-tight containers.

     Caution.—­All poison containers and all utensils used in the
     preparation of poison should be kept plainly labeled and out of
     reach of children, irresponsible persons, and live stock.

     A spoonful of the poisoned grain scattered about the used entrances
     of a mound is sufficient, and prebaiting is not necessary, as with
     prairie dogs.

A word of caution should perhaps be offered in connection with control measures.  As man has come to occupy a greater portion of the earth’s surface, and as he has become more and more the master of his environment, he has inevitably disturbed the relationships of the birds and mammals about him, has upset the balance of nature.  If he kills the carnivorous species because of their depredations on game and live stock he must be prepared to cope with the increased hordes of rodents which feed on vegetation and on which the carnivorous animals act as a check.  If he destroys the rodents, he may remove the checks on certain noxious plants or insects.  One control measure often necessitates the adoption of another.

This is not to argue against control measures, for if our harmful species were not controlled, agriculture in many sections would be impossible.  Control measures, however, should be scientifically founded and applied.  The indiscriminate slaughter of supposedly harmful species of birds and mammals in the guise of benefiting agriculture may do far more harm than good.  Many of the species which do some harm do far more good.  The exact status of each suspected species should be carefully determined through an adequate scientific investigation.  If the species is condemned, sound control measures should be thoroughly applied.