474 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1920. 



made of levulose, maltose, raffinose, dextrose, lactose, dextrine, and 

 various varieties and mixtures of honeys and sugar sirups; (3) bitter 

 foods — quinine, strychnine, and picric acid, mixed with candy, and 

 chinquapin honey alone; (4) sour foods — lemon juice, acetic, hydro- 

 cloric, sulphuric, and nitric acids, mixed with honey; and (5) salty 

 foods — various sodium and potassium salts, including our common 

 table salt, mixed with candy. 



The results obtained clearly demonstrate that bees have likes and 

 dislikes in regard to foods, and it seems that their faculty to discrimi- 

 nate between foods is more highly developed than ours, because they 

 can distinguish differences between the foods fed to them better than 

 the writer. The candies containing strychnine and quinine best illus- 

 trate this point. Equal amounts of these two bitter salts were used ; 

 but when the writer tasted the candies containing them, little or no 

 difference in bitterness could be detected, although, judging from the 

 number of bees that ate them when the two foods were fed alone, the 

 bees distinguished a marked difference between them. 



As a general rule, foods agreeable to us are also agreeable to bees, 

 but there are a few marked exceptions. All foods scented with pepper- 

 mint are pleasant to us, but repellent to bees. The writer does not care 

 for candy containing potassium ferrocyanide, but bees are rather fond 

 of it, and it does not seem harmful to them. 



In regard to the repellents used, the few experiments performed do 

 not warrant definite deductions, but the results indicate that lime- 

 sulphur and kerosene are the strongest of the repellents used, while 

 formic acid repels the least and carbolic acid the most among the acids. 

 That the acids as a rule are not better repellents may possibly be ex- 

 plained by the fact that bees are more or less accustomed to the odors 

 from the acids found in their foods and various secretions. 



The results obtained demonstrate that bees like honey best of all 

 foods and that they are able to distinguish marked differences be- 

 tween various kinds of honeys. Substitutes for honey as food for bees 

 may be better than honey in a few instances, but these investigations 

 indicate that no substitute can be had which will be liked by bees as 

 well as the best pure honey. 



The fact that bees must first eat more or less of the foods before be- 

 ing able to discriminate differences between them, unless they contain 

 repellents, indicates that bees have a true gustatory sense, providing 

 this discrimination is not accomplished by means of the olfactory 

 sense. Since this point can not be determined experimentally, our 

 only criterion is to make a thorough study of all the sense organs on 

 and near the mouth parts. This part of the work was accomplished, 

 and only two kinds of sense organs were found, as may be seen by re- 

 ferring to the innervated hairs, marked b, c, e, and /, and to the olfac- 



