Chap. I. SECRETION OF NECTAR. 37 



either in the nectary or on the hibellum of 0. morio, 

 fusca, 7nilitaris, maculata or latifolia. I have looked 

 to all our common British species and could find no 

 trace of nectar; I examined, for instance, eleven 

 flowers of 0. maculata^ taken from different plants 

 growing in different districts, and taken from the most 

 favourable position on each spike, and could not find 

 under the microscope the smallest bead of nectar. 

 Sprengel calls these flowers " Scheinsaftblumen" or 

 sham-nectar-producers ; — he believes that these plants 

 exist by an organized system of deception, for he well 

 knew that the visits of insects were indispensable for 

 their fertilisation. But when we reflect on the incalcul- 

 able number of plants which have lived during a great 

 length of time, all requiring that insects should carry 

 the pollen-masses from flower to flower in each gene- 

 ration ; and as we further know from the number of the 

 pollen-masses attached to their proboscides, that the 

 same insects visit a large number of flowers, we can 

 hardly believe in so gigantic an imposture. He 

 who believes in Sprengel's doctrine must rank the 

 sense or instinctive knowledge of many kinds of 

 insects, even bees, very low in the scale. To test 

 the intellect of moths and butterflies I tried the 

 following little experiment, which ought to have been 

 tried on a larger scale. I removed a few already- 

 opened flowers on a spike of 0. pjramiclalis, and 

 then cut off about half the length of the nectaries 

 of the six next non-expanded flowers. When all the 

 flowers were nearly withered, I found that thirteen 

 of the fifteen upper flowers with perfect nectaries 

 had their pollinia removed, and two alone had their 

 pollinia still in the anther-cells ; of the six flowers 

 with their nectaries cut off, three had their pollinia 

 removed, and three were still in place ; and this in- 



