RELATED STUDIES AND CRITIQUES. 167 



rected by the odors carried by currents of air and thus reach the flowers 

 that exhale them. As soon as they approach sufficiently near for sight 

 to intervene, they fly directly to the flowers in response to guidance by 

 vision. Color likewise serves to attract, in the absence of odor previously 

 perceived, when the chances of the flight bring them near a flower. They 

 then visit the latter if the odor is pleasing, or disdain the flower if the odor 

 is unpleasant. 



In a more extensive paper (1903:1), Perez communicated the results of 

 further experiments and discussed at some length the points of difference 

 between Plateau and himself. When fallen flowers of Glycine were inter- 

 spersed with bits of paper of the same color, a honey-bee inspected them, 

 but flew away before landing, to seek nectar in some of the flowers. Small 

 balls of rose paper were strung on a pin, which was fixed on the end of a 

 leafy shoot of Symphoricarpus or on a shoot from which the flowers had 

 been removed, and in some cases all the open flowers of a cluster were 

 replaced by similar balls of paper. Two honey-bees inspected the paper- 

 balls for a moment, while a bumble-bee gave them more extended 

 attention. When the rose flowers of a currant were hidden by means of 

 green leaves and bits of cloth of the same color placed near them, several 

 honey-bees were deceived by the latter, though they finally found the 

 masked clusters. Similar results were obtained from a small orange tree 

 ornamented with small pieces of white paper. The addition of honey 

 to the branches of a laurustine ornamented with squares of white and blue 

 paper quickly attracted honey-bees, which went first to the colored papers. 

 Disconcerted, they began an agitated search for the honey and finally 

 found it. 



Perez's critique of Plateau's work. — Perez pointed out that the use 

 of large surfaces of colored cloth by Plateau to demonstrate the indifference 

 of insects to color was incapable of furnishing actual evidence on this point, 

 since insects care nothing for color in itself, but only as a sign of the food 

 they are seeking. The same failure to recognize the significance of the 

 resemblance of small bits of cloth to flowers in contrast to large pieces was 

 regarded as vitiating Plateau's results with bright standards placed near 

 masked composite heads. A just criticism of the latter's statement that 

 all the results obtained with colors were illusory because of Graber's dis- 

 covery, was based upon the fact that this showed insects, like man, to 

 receive different impressions from the light of different parts of the spec- 

 trum, and that it is immaterial whether their perceptions are the same as 

 ours, since they possess a scale of luminous sensations. Experiment based 

 upon the use of colored objects is legitimate in every respect and to proscribe 

 it would be only to carry one's scruples to excess. Attention was also called 

 to the obvious discrepancy of Plateau's own conclusions as to the importance 

 of color, involved in the two statements, "Neither form nor color seems 

 to have any attractive role" (1895), and "I admit that this vague visual 

 perception can guide the insect toward the flower mass, concurrently with 

 smell but to a much less degree" (1899). 



In regard to the errors committed by pollinators, P6rez noted that 

 Plateau invoked smell to explain the attraction of flowers containing nectar, 



