1910] CURRENT LITERATURE 391 
types of development. In the hemiparasite Melampyrum pratense, GAUTHIER*S 
found that the seeds germinated without any stimulus from other organisms, and 
that the seedlings had a short independent existence, during which 
branched freely. Root hairs developed in abundance, many of them consisting 
of two or three cells, but before the food stored in the seed became exhausted, the 
root hairs began to be replaced by haustoria which penetrated the roots of the 
host. Trees with mycorhiza upon their roots were the hosts, the beech much 
more frequently than other species. Failure to effect a contact with a suitable 
host resulted in the early death of the seedlings. The investigator stated that the 
seeds, in common with those of Rhinanthus, Euphrasia, and Pedicularis, would 
not germinate if allowed to become dry. 
HEINRICHER studied the same species,?° obtaining results essentially similar 
to the above, but he claims?’ that in general the seeds of Rhinanthus, Euphrasia, 
and Pedicularis are not so sensitive to desiccation, but retain their vitality for 
several months, although some of them germinate only during the spring. He 
has studied the group extensively, and in the recent article summarizes the life 
history of a highly specialized type discussed in a former paper.? The seeds of 
Tozzia germinate only with the chemical stimulus afforded by the roots of the host, 
its cotyledons never appear above the soil, and for two or three years it is a sub- 
terranean holoparasite. Finally it sends up an aerial shoot which becomes green, 
flowers, and produces seeds. As the seeds mature the plant dies, each individual 
flowering once only.—Gro. D. FULLER. 
Vegetation of the Danish West Indies.—As a result of further study of the 
halophytic vegetation of the Danish West Indian Islands, BorGESEN”? has modi- 
ed somewhat his former classification of the plant societies involved, and now 
istinguishes a hydrophytic vegetation composed of sea grass and algae, and a 
halophytic g the muddy soil vegetation, the sand strand vegeta- 
tion, and the rocky coast vexetalion: The muddy soil vegetation is made to 
include the mangrove, Salicornia, and Conocarpus formations. The author 
places emphasis upon the influence of exposure and soil consistency as the deciding 
factors in limiting the mangrove formation, which he defines as a formation of 
treelike evergreen plants growing on the sheltered shores, partly in shallow salt or 
25 haere L., Sur le parasitisme du Melampyrum pratense. Rev. Gén. Bot. 
20:67-84. 19 
26 aa, E., ant griinen Halbschmarotzer, V. Melampyrum. Jahrb. 
Wiss. Bot. 46:273-376. 
27 
337- 1909. 
28 
i oad. des graines des plantes parasites. Rev. Gén, Bot. 21:329- 
———., Die griinen Halbschmarotzer. III. Bartschia und Tozzia. Jahrb. 
Wiss. Bot. 36:665-752. 1901. 
29 BORGESEN, F., Notes on the shore vegetation of the Danish West Indian 
Islands. Bot. Tidssk. 29:201-259. pls. 3-6. 1909. 
