BIBLIOGRAPHY 



393 



Pearsall, W. H. The Aquatic and Marsh Vegetation of Esthwaite 



(1917-1918) Water. Journ. of Ecology, Vol. v. 1917, pp. 180-202 



[p. 288] arid Vol. vi. 1918, pp. 53-74, 12 text-figs. 



(A detailed ecological survey of a Lancashire lake.) 



Pearsall, W. H. (1918) On the classification of Aquatic Plant Communities, 

 [p. 288] Journ. of Ecology, Vol. vi. 1918, pp. 75-83. 



(The author regards aquatic, fen and moor successions as 

 together forming a unit and leading up to the one formation 

 moor.) 



Perrot, . (1900) Sur les organes appendiculaires des feuilles de 



[p. 169 and Fig. no, certains Myriophyllum. Journ. de Bot. T. xiv. 1900, 

 p. 170] pp. 198-202, 5 text-figs. 



(An account of the peculiar processes borne by the leaf of 

 Myriophyllum verticillatum and M. spicatum, which the author 

 regards as pluricellular caducous trichomes.) 



Ueber einige deutsche Nymphaen. Bot. Zeit. Jahrg. 

 12, 1854, pp. 172-175. 



(A critical article in which special stress is laid on the import- 

 ance for systematic purposes of ascertaining the characters of 

 the ripe fruit.) 



Pieters, A. J. (1894) The Plants of Lake St Clair. Bull. Michigan Fish 

 [p. 288] Commission, No. 2, 1894, 12 pp., i map. 



[An ecological study in which the zonation of the plants 

 observed in Lake St Clair is compared with that recorded by 

 Magnin, A. (1893) for the Jura lakes.] 



Pfeiffer, L. (1854) 



Pieters, A. J. (1902) 

 [p. 291] 



Contributions to the Biology of the Great Lakes. 

 The Plants of Western Lake Erie, with Observations 

 on their Distribution. Bull. United States Fish 

 Commission, Vol. xxi. 1902 (for 1901), pp. 57-79, 

 10 pis., 9 text-figs. 

 (An ecological study.) 



Planchon, J. E. (1844) Observations sur le genre Aponogeton et sur ses 

 [p. 314] afnnites naturelles. Ann. d. sci. nat. Ser. in. Bot. 



T. i. 1844, pp. 107-120, i pi. 



(The author describes Aponogeton distachyus and brings 

 forward evidence for removing it from the neighbourhood of 

 Saururus and placing it in a sub-order between the Alismaceae 

 and Juncaginaceae.) 



Planchon, J. E. (1853) fitudes sur les Nympheacees. Ann. des sci. nat. 

 Ser. in. T. xix. 1853, pp. 17-63. 

 (A systematic account of this family.) 



Pond, R. H. (1905) 

 [p. 264] 



Contributions to the Biology of the Great Lakes. 

 The Biological Relation of Aquatic Plants to the 

 Substratum. University of Michigan. Inaug. Diss. 

 Ann Arbor, 1905, 43 pp., 6 text-figs. 

 (This paper contains important experimental work relating to 

 the function of the roots in aquatic plants.) 



