228 Floristik, Geographie, Sj^stematik etc. 



Ulei Hörold, Liicunia macrophylla K. Krause, Poiiteria jiivuana K. 

 Krause, Sideroxylon Ulei K. Krause, Bathysa peruviana K. Krause, 

 Hillia Ulei K. Krause, Cassiipa jiiniana Schum. et Krause , C. scar/a- 

 tina Schum. et Krause, Schradera siihandina K. Krause, Sommern 

 laiiceolata Krause, Retiniphylliim fucJisioides K. Krause, Dolichodel- 

 phys chlorocrater K. Schum. et K. Krause, Posoqueria speciosa Krause, 

 Basanacantha Wittii Schum. et Krause, Alibertia tenitifolia Krause, 

 A. pilosa Krause, Guettarda nitida Krause, Psychotria epiphytica 

 Krause, P. innndata Krause, P. nana Krause, P. Ernesti Krause, 

 Palicoiirea Lagesii Schum. et Krause. P. roseiflora Schum. et Krause, 

 P. Ulei Schum. et Krause, P. nigricans Krause, P. lasioneiira Krause, 

 P. juniana Krause, P. iqiiitoensis Krause, P. Ponasae Krause, Ura- 

 goga silvicola Krause, Rudgea lasiostylis Krause, Coussarea bryoxenos 

 Schum et Krause, C. hrevicaidis Krause, Faramea jiiruana Krause, 

 Boweria campinonim Krause, Adenocalymma sclerophyllum Sprague, 

 Distictis angitstifolia K. Schum., Cydista hracteomana K. Schum., 

 Pleonotoma aiiricidatum K. Schum. 



W. Wangerin (Königsberg i. Pr.). 



West, G., A Further Contribution to a Comparative 

 Study of the dominant Phanerogamic and Higher 

 Cryptogamic Flora of Aquatic Habit in Scottish Lakes. 

 (Proc. roy. Soc. Edinburgh, Session. XXX. 2. p. 65 — 182. with 

 124 ill. 1909—10.) 



This paper is a continuation of a similar comparative record in 

 Vol. XXV, Part. 11. Proc. roy. Soc. Edin., and gives a detailed 

 floristic account of dominant and abundant plants in individual 

 lochs of areas which are designated: Area IV. N. W. Kirkcud- 

 brightshire: Area V. S. E. Kirkcudbrightshire: Area VI. 

 Wigtownshire: Area VII. Fife and Kinross. The account 

 suggests comparisons between the flora of highland waters more 

 or less peaty in character, and that of lowland lochs not peat}" and 

 chiefly situated in agricultural districts. There are abundant notes 

 on the striking ph3"sical peculiarities of the individual lochs, and 

 observations on factors determining the abundance and character 

 of the prevalent Vegetation e. g. the effect of the contiguity of grass 

 land to the lochs oi the southern moors, where the dead stems of 

 Molinia, Nardiis, and Scirpits caespitosa, transported by wind and 

 stream and finally deposited in the lochs, form a layer of detritus 

 which restricts the depth to which Vegetation extends; the similar 

 effect of masses of floating Algae — characteristic of lochs in rieh 

 land and especially of waters polluted with sewage — in excluding 

 bottom Vegetation; the work of birds in distribution and extermina- 

 tion of species; etc. 



The general conclusions formed are: 1. As to distribution. — 

 That without a fuller knowledge of the relations existing between 

 organism and environment, general laws governing the geographica! 

 distribution of aquatic plants in the areas in question cannot be 

 deduced: restricted distribution is often associated with local 

 abundance. 



2. As to origin of aquatic species. — That certain mutable forms 

 have exhibited a tendency to an aquatic habit which they have 

 adopted as convenient rather than necessar}^- certain marsh forms 

 commonh^ take on the aquatic habit. 



3. As to variability of aquatic species. — That the plastic nature 



