314 The Living Plant 



of strange parasite. Almost immediately, during the flight of 

 the insect from flower to flower in fact, these pollen masses 

 droop on their stalks, and hang down in such position that when 

 the insect probes into a new flower they do not strike the anther 

 but are pressed down directly on the sticky 

 stigma, which holds them tenaciously. And 

 thus is cross pollination effectively per- 

 formed. 



These three cases have been chosen not 

 because they are especially remarkable, but 

 because they illustrate several different 

 features of cross-pollination methods. In- 

 deed, the number of equally-striking cases 

 is le S ion > requiring whole volumes for their 



pollinates the Habenaria adequate description; and many of the ar- 



of figure 113; the pollen . . 



masses are attached to rangements might well stagger belief were 



its eyes. (Reduced from , -. ,, , , , . . , 



Gray's structural they not fully confirmed by the critical 

 studies of large numbers of competent in- 

 vestigators. But while we cannot take space to describe any more 

 individual cases, for which the reader, if interested, may turn 

 to the works described in the footnote,* we must follow some- 

 what farther a few of the matters brought up in the foregoing 

 discussion. 



* The principal works upon cross pollination likely to prove of interest or use to 

 the reader are the following: The foundation of all is Sprengel's book entitled (in 

 translation, for the work is in German) Nature's Secret displayed in the Construction 

 and Pollination of Flowers (1797), a classical work a half century ahead of its time, 

 and a treasury of accurate information on its subject, though it missed, of necessity, 

 the central illuminating idea of the value of cross as compared with close pollination. 

 Next in importance came three of Darwin's greatest books, The Various Contrivances 

 by which Orchids are Fertilized by Insects, The Effects of Cross and Self Fertilization in 

 the Vegetable Kingdom, and Different Forms of Flowers on Plants of the same Species, 

 which three works contain a greater amount of new observation and illuminating 

 explanation than any others we possess. The first general summary of the entire 

 subject was Miiller's Fertilization of Flowers, a translation of a German work, which 

 is admirable in all respects, and superseded only by the cyclopedic work by Knuth, 

 Handbook of Floral Pollination, just completed, likewise a translation from the 



