RECENT INVESTIGATIONS. 203 



The honey was placed in a small porcelain dish covered with gauze, so that 

 the odor could escape but the honey itself could not be reached and thus 

 exhausted. This was exposed on the threshold or the top of a hive and 

 observed for a quarter to a half hour during the period of the best morning 

 flight, the temperature, humidity, wind direction, and condition of the sky 

 being recorded, as well as the honey increase of a test hive and the kind and 

 condition of the flowers available. On June 1 and July 6 no bees were 

 attracted to the honey, while on April 30, May 15, June 15, July 15, and 

 August 1, the respective numbers were 7, 3, 6, 7, and 1. On August 15, 

 13 bees were noted, 23 on August 30, a host on September 16, and 15 to 20 

 on the 30th. The most striking relation was the inverse one to the number 

 and abundance of nectariferous species and the nectar flow. The visitors 

 to the honey were few or none until the flowers decreased greatly or dis- 

 appeared altogether, when they increased from two to several fold. Zander 

 regarded the observations of June 1 and July 6 as the only ones that sup- 

 ported Forel's view as to the bee's feeble sense of smell for honey, but it 

 would appear that all the observations that yielded but 1 to 7 visits should 

 also be considered as evidence for this, if those that gave 20 to many vis- 

 itors be adduced in proof of a keen sense of smell. Interesting as the 

 experiments are, they fail to reckon sufficiently with the effect of habit 

 on the one hand and the tendency of bees to attract others on the other, 

 to be entirely conclusive. They do show, however, that the sense of smell 

 is psychic as well as physical, in that the stimulus of the odor of honey is 

 much less effective in the midst of the obsession produced by an abundant 

 flow of nectar. 



The sense of smell in the honey-bee. — Frisch has supplemented his 

 studies of the attraction exerted by color by a second outstanding research 

 on the sense of smell in the honey-bee (1919:1). As this likewise became 

 available only after the present book was in type, it must suffice to 

 indicate the main heads of his treatment and to give the essence of his 

 summary. The main divisions of his treatise, which has the proportions 

 of a book, are as follows: (1) exposition of the experimental technique, and 

 discussion of the question whether bees are attracted by the odor of flowers; 

 (2) ability of the honey-bee to discriminate between different odors; (3) 

 odor and color; (4) memory of the honey-bee for odor and color; (5) do 

 scentless inconspicuous flowers that are much visited by bees have a fra- 

 grance imperceptible to us? (6) the odor of honey; (7) the fineness of the 

 sense of smell in the honey-bee (the "minimum perceptibile ") ; (8) experi- 

 ments with mixed odors; (9) the biological significance of the fragrance of 

 flowers; (10) experiments with odorous substances of different chemical 

 composition but similar odor; (11) training with lysol, skatol, etc., a con- 

 tribution to the psychology of the honey-bee; (12) summary. 



The first questions to be decided were whether the honey-bee perceives 

 the odor of flowers and whether it is guided by such perception in its visits 

 to flowers. The answer in both cases is affirmative, since training for flower 

 odors has always met with complete success. But in addition to odor 

 itself, its quality must be taken into account. Bees trained to the fragrance 

 of acacia visit this alone and are not in the least attracted by the odor of 

 the rose or lavender. Bees trained to the odor of the oil from orange-peel 



