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1904] BRIEFER ARTICLES 147 
ture of clay and gravel. Directly underneath the stratum of the 
original surface soil which contained the seeds was a very thin layer of 
clay, below which was the bed of gravel and sand. 
These seeds were not buried sufficiently deep to prevent them from 
being frozen, but the layer of clay above served quite well to protect 
them from the air, thus diminishing the respiratory activity, and the 
gravel and sand beneath furnished the best possible conditions of 
drainage. Under such favorable conditions the vitality of many seeds 
might be preserved, when buried in the soil, for a score of years or 
more.—J. W. T. Duve., U. S. Department of Agriculture, Washington, 
D.C. 
CUMAPHYTISM IN ALARIA. 
(WITH TWO FIGURES) 
Amonc the species of Alaria displayed upon the kelp beds of the 
Minnesota Seaside Station, the one named A/aria nana by Mr. H. F. 
Schrader? has been found to show a somewhat remarkable adaptation 
to the surf habitat which it shares with Poste/sta palmacformis Rupr. 
along the Straits of Fuca. Plants of A/aria nana are found inter- 
mingled with Postelsia and form for the most part an undergrowth 
between the trunks of the larger kelp. Upon few rocks have there 
been found unmixed growths of Alaria. Last summer, however, I was 
enabled to examine two or three beds of A/aria nana which had not 
come under the observation of Mr. Schrader. A series of plants was 
collected for the laboratory work in the University of Minnesota, and 
two of them have been photographed to accompany these notes. 
Their consideration will make it apparent how strongly the Alaria 
type may become adapted to existence in the surf. 
When growing intermixed with Postelsia the common form of 
Alaria nana is as shown in fig. z. The plants will not average more 
than 20™ in length. In these plants the mid-lamina is well developed, 
and the gonidiophylls are comparatively slender and their entire sur- 
face, with the exception of a narrow marginal region, is soral. ‘Toward 
the base of a Postelsia formation the plants of A/aria nana average 
somewhat larger, and the stipes are not erect, but decline upon the 
rocks. Higher in the formation the size of the plants diminishes and 
the stipes become more erect, until well toward the top the erect habit 
?SCHRADER: Observations on A/aria nana, sp. nov. Minn. Bot. Studies 3: 157. 
1903. 
