WHY PERFECT FLOWERS NEED TO ATTRACT INSECTS. 



21 



and are visited by bees. Is their nectar provided only for the good of the bee ? 

 We might suppose so, until we come to know the remarkable fact that, unless 

 visited by insects, they seldom ripen a pod or set a seed. The Showy Dicentra, 

 which comes from Japan or Northern China, rarely sets fruit in our gardens in 

 any case. But the wild species of Corydalis and Fumitory, which have their 

 flowers on the same plan, seed freely enough. Yet when the blossoms are kept 

 covered with fine gauze, so as to exclude insects, little or no seed is produced. 

 Evidently then, for some reason or other, insects sucking their honey are not only 

 useful, but needful even to such blossoms. Why they should be needful remains 

 to be seen. 



Fig. 9. Plower of Bleeding-heart, Dicentra spectabilis Fig. 10 Same, ^th the tips of the united inner petals pushed 

 to one side. Fig. 11. Tips of the six stamens and pistil, which are exposed in Fig. 10, here separated and dis- 

 played, magnified, 



38. If it be wonderful that such flowers as the last do not well fertilize without 

 help, although constructed, as we should say, expressly to do it, equally wonderful 

 is it to find blossoms with anthers and stigma placed close together, but with some, 

 obstacle interposed, as shown on near examination ; which looks as if the object 

 were how not to do it. 



39. Iris-flowers are of this sort. There is a stamen to each of the three stig- 

 mas, and close beside it. Behind each stamen and partly overhanging it is a 

 petal-like body, peculiar to Iris or Flower-de-Luce : these three bodies, appearing 

 like supernumerary petals, are divisions of the style, in a peculiar form, notched 

 at the end ; under the notch is the stigma, in the form of a thin plate. We 

 notice that the stigma is higher than the anther ; but that is only a part of the 



