Polymorphism in the Flower of Silene maritima. 7 
LITERATURE CITED. 
Gothan, W. Review of E. C. Jeffrey’s “The Genus Sequoia." Just’s 
Botanischer Jahresbericht, Vol. 31, 1903. 
,, “ Zur Anatomie lebender und fossiler Gymnospermen Holzer.” 
Abhandl. Konigl. Preuss. Geol. Landesanstalt, Neue 
Folge, Heft 44, 1905. 
,, “ Die Fossilen Holzreste von Spitzbergen.” Handl. Kgl. 
Svensk. Vetenskap. Akad., Band 45, No. 8, 1910. 
Jeffrey, E. C. “ The Comparative Anatomy and Phylogeny of the Coniferales.” 
Part I.—The Genus Sequoia, Memoirs Boston Society 
of Natural History, November, 1903. 
,, “ Traumatic Ray Tracheids in Cunninghamia Sinensis." Annals 
of Botany, 22, 1908. 
,, “ A Fossil Sequoia from the Sierra Nevada.” Bot. Gaz. 38, 
1904. 
Mayr, Heinrich. “ Die Waldungen von Nordamerika.” Miinchen, 1890. 
I’enhallow, D. P. “A Manual of the North American Gymnosperms.” 
Boston, 1907. 
Thompson, W. P. “ On the Origin of Ray Tracheids in the Coniferae.” Bot. 
Gaz., 50, 1910. 
POLYMORPHISM IN THE FLOWER OF SILENE 
MARITIMA. 
By E. J. Salisbury, B.Sc., F.L.S. 
(Quain Student in Botany , University College, London). 
[With Plate I and a Text-Figure], 
f IHE material used in the present paper was obtained in the 
summers of 1910 and 1911 whilst engaged as a member of 
Professor Oliver’s ecological party in a study of the shingle beach 
flora at Blakeney Point in Norfolk. Here, as on nearly all pebble 
beaches, the Sea Campion ( Silene maritima) is one of the most 
striking features of the vegetation, and it would probably be difficult 
to find a locality better suited to the study of this particular plant. 
At its distal extremity the main beach is, to a large extent, covered 
by sand dunes; and where the depth of sand is not great the Sea 
Campion is perhaps even more prevalent on this than on the shingle 
itself. The incursion of the typical sand dune plants soon, how¬ 
ever, drive it out from the association. 
Constantly coming before one’s notice, the marked difference 
which the flowers exhibit is perhaps the most vivid impression that 
the plant presents. But here, and probably in many cases where 
there appears to be great structural range, further analysis shows 
