— 254 — 



Natural history of the Danish flowering plants, I. Monocotyledones x ), 

 I examined the Danish species anatomically and found that several 

 of the anatomical characters in the vegetative parts are much more 

 fixed than are many of the morphological characters in the same 

 parts. And time after time I succeeded in the pointing out of so 

 many differences that most species could be determined by only 

 the smallest bit of a stem. The characters used by me are taken 

 either from the stem only or from both the stem and the leaves; 

 certainly in other parts of the plant, for instance in the root, there 

 are anatomical characters that surely might be employable in the 

 determination; when, however, at the determination of species and 

 forming of species-groups I have used but anatomical characters 

 taken only from the stem and the leaves, it is partly because that 

 only those parts of the plants are always to be had. 



Having finished the revision of the Danish Potamogeton-species 

 given in my before named book, I have, as far as possible, extended 

 my anatomical investigations also to foreign species, intending to 

 bring about a new and better basis for an eventual monograph of 

 the genus Potamogeton. Such a work, however, implies an anato- 

 mical examination of all the species and even of a number of indi- 

 viduals of every species ; but it is very difficult to procure materials 

 of all hitherto diagnosed species; at any rate there are many species 

 of which it has been impossible to me to get materials. Add to 

 this that, to the determination of individuals belonging to pre- 

 viously anatomically examined species, you might as a rule well 

 use bits of dried plants soaked in water, but of course it is best 

 that for the fundamental anatomical investigation of every single 

 species the material is of live plants or of plants preserved in spirit. 

 This material, moreover, must be so complete that the plant can 

 be identified by the species-description in hand, what is often im- 

 possible with the herbaria-specimens. Especially it has been diffi- 

 cult to procure material of not-European species. Though I have 

 happened to examine many foreign species — namely because my 

 friend the ardent Potamogeton-collector and Potamogeton-judge 

 I. Baagöe, apothecary at Næstved, has put his great and beautiful 

 collection at my disposal — it will be a long time yet before we 

 shall succeed in procuring sufficient material of all the species. 



] ) C. Raunkiær, De danske Blomsterplanters Naturhistorie. I. Enkimbladede. 

 LX IX + 724 Pag. Med 1089 Figurer i 293 Figurgrupper. Kjøbenhavn 1895—99. 

 Here list of literature. 



