THE CROW AND ITS RELATION TO MAN. 75 



seed with any of these substances in such small quantity or dilute form as not 

 to injure the germ is a waste of time, for the slight taste or odor imparted is 

 soon dissipated in contact with the soil. 



Mixing pulverized gum camphor with the dry grain and storing it in a closed 

 vessel for some days has been recommended as an efficient treatment. With us 

 the results were entirely negative. Little or no odor was imparted to the grain. 

 Pine tar was used in our experiments. It has a strong odor, but leaves the 

 grain too sticky to work in a planter. 



Coal tar makes an ideal coating of a rich brown color and a persistent, gassy 

 smell. It dries nicely, is not in the least sticky, and will work well in a planter. 

 Wet the grain with a little warm water before stirring in the tar. A teaspoon- 

 ful of the latter will be sufficient for a peck of corn. The mass must be 

 thoroughly mixed and then dried before attempting to plant. 



Valuable experiments showing the effect upon seed grain of the 

 various deterrents against crows were conducted by B. M. Dugger 

 and M. M. McCool at the Agricultural Experiment Station of Cornell 

 University. The following is an extract from their report: 1 



Considering the practices now more or less commonly employed, it seemed 

 desirable to give the coal tar a careful experimental trial, and, at the same time, 

 to employ other substances with objectionable odors or tastes. Accordingly, 

 experiments were arranged for the treatment of seed with the following sub- 

 stances, namely, coal tar, pine tar, oil of turpentine, anilin oil, and 

 pyridine. * * * 



Some difficulty was anticipated in securing a more or less equal distribution of 

 the small amount of tar upon so large a volume of seed, but it was found that 

 this could be accomplished by repeated stirring or shoveling of the seed. Tar 

 at the rate of one or two tablespoonfuls per 10 quarts of seed was sufficient 

 effectively to coat almost every seed in the mass. This was true in the case of 

 both the coal and the pine tars. It was therefore evident that any of the 

 materials mentioned could be employed so far as convenience is concerned. In 

 employing pyridine and anilin oil 10 per cent solutions were used, and with 

 turpentine a 10 per cent emulsion. In these solutions the seeds were soaked 

 for a period of two or three hours. 



After treatment the seeds were sown in pots containing a sandy loam soil, 

 this in order to determine the effect of the treatment given upon germination. 



The results of this germination test showed that seed treated with 

 pine tar, coal tar, and pyridine solution (three hours) gave the most 

 favorable results — a germination of between 98 and 100 per cent, 

 which was equal to that of the untreated seed used as a check. Tur- 

 pentine emulsion (three hours), turpentine emulsion (four and one- 

 half hours), and anilin oil solution (three hours) gave percentages 

 ot 38, 8, and 0, respectively. The report continues — 



The results of these experiments demonstrate conclusively, it would seem, that 

 the use of tar in no way prevents germination. It might be further stated that 

 germination was not retarded by the use of tar in the experiments above men- 

 tioned. Again, varying quantities of the tars were also employed with similar 

 results. In other experiments the seeds were planted in moist paper and com- 



1 Circ. 6, Cornell Univ. Agr. Exp. Sta., pp. 14-16, May, 1909. 



