128 THE TEACHING BOTANIST 



the topography or physiognomy of vegetation, and the 

 distribution of the different forms, there is a most 

 admirable work by Warming, written in Danish, and 

 translated into German under the name " Oekologische 

 Pflanzengeographie," and now being translated into 

 English. More recent, and noteworthy for its great 

 authority, its remarkably full and clear treatment of 

 its subject, and its superb illustrations, is Schimper's 

 " Pflanzengeographie auf physiologischer Grundlage." 

 This work should be in every botanical library for its 

 illustrations alone, even if one cannot read German. It 

 supplies by far the best collection of botanical, espe- 

 cially ecological, photographs ever published. One of 

 the most important phases of ecology is that of the . 

 locomotion of pollen (often wrongly called cross-ferti- 

 lization); and on this there is a most valuable work by 

 M tiller, translated into English by Thompson, under the 

 title " Fertilisation of Flowers." This is in great part 

 arranged on the dictionary principle, so that it is easy 

 to find out what is known of the pollination of any 

 particular flower. Much has been discovered since its 

 publication ; and a recent work by Knuth, "Handbuch 

 der Bliitenbiologie," in two volumes with more to come, 

 brings the subject down to this date, at least for Euro- 

 pean plants. On the attractive subject of seed-loco- 

 motion there is no single large work in English, but 

 an excellent little book is Beal's " Seed Dispersal." 

 Darwin's works on fertilization of flowers, and his 



