HISTORICAL DEVELOPMENT OF FLOWER POLLINATION 25 



latter gives (op. cit.), moreover, a grouping of plants according to their floral 

 arrangements, and seeks to establish by statistics, the connection between floral 

 mechanisms and the bodily structure of the visitors. The floral statistics begun 

 by Miiller were later on extended by others, especially by Loew, MacLeod, and 

 myself. 



While many investigators busied themselves with the representation of general 

 floral arrangements, a still larger number investigated the mechanisms for pollination 

 in individual flowers, or groups of flowers. These researches, which have been 

 carried out in all parts of the world, cannot possibly be even indicated here, and 

 reference is therefore made to the bibliography. 



It must be the aim of research in Flower Pollination to make out the adaptations 

 of all flowers and their pollinators, and this end can only be approached if such 

 investigations are systematically carried on • in as many small and clearly demarcated 

 areas as possible. For the attainment of this end, it is necessary that numerous 

 observers should take part in the work, and that the earth should be covered with 

 a net-work of stations ' for the study of flower pollination. As yet, but few attempts 

 have been made in this direction. In the first place there must be mentioned, 

 as standing far above all other attempts, the work of Hermann Miiller (' Alpenblumen,' 

 Leipzig, 1 881), already referred to several times. It contains the observations of 

 this genial and untiring author, made in the East Alps (especially in the Canton 

 Graubiinden) during the years 1874-9. 



Of similar worth is MacLeod's book, ' De Pyreneefinbloemen en hare bevruchting 

 door insecten' (Ghent, 1891). It contains investigations and observations in flower 

 pollination made by MacLeod in the Pyrenees during the years 1889 and 1890. 



The same investigator, in his work, 'Over de bevruchting der bloemen in het 

 Kempisch gedeelte van Vlanderen' (Ghent, 1893-4), gives an account of the floral 

 arrangements of the plants of the Kempian part of Flanders, and enumerates many 

 floral visitors. 



O. Kirchner in his 'Flora von Stuttgart' (1888) describes the floral arrange- 

 ments occurring in that neighbourhood, so far as known up to his time. 



C. Verhoeff in his work, ' Blumen und Insekten der Insel Norderney ' (Nova 

 Acta d. Kais. Leop.-Carol. Deutschen Akad. der Naturf., Ixi, 1893), gives an 

 exhaustive account of the mutual relations existing between flowers and insects in 

 that island. 



My own memoirs on the same lines refer for the most part to the relations 

 subsisting between flowers and their visitors on the islands in the German North 

 Sea. A comprehensive work of this kind is ' Blumen und Insekten auf den nord- 

 friesischen Inseln' (Kiel, 1895). This has been supplemented by my publications, 

 ' Weitere Beobachtungen uber Blumen und Insekten auf den nordfriesischen Insehi ' 

 (Kiel, 1895), 'Blumen und Insekten auf den Halligen ' (Ghent, 1894), and 'Blumen 

 und Insekten auf der Insel Helgoland' (Ghent, 1896). I further conducted a 

 partially systematic investigation into flower pollination on the Island of Capri (1892), 

 in Thuringia (1894), on the Island of Rugen (1896), and since 1877 in Eastern 



• Cf. P. Knuth, 'Blumen und Insekten auf den nordfriesischen Inseln,' preface. 

 » Cf. P. Knuth, 'Die Besncher derselben Pflanzenart in verschiedenen Gegenden," Part 3, 

 ccnclnsion. 



