1913] CURRENT LITERATURE 245 
The gemmae at maturity measure 0.5mm. in diameter. The adult leaf 
measures 0.8 mm. in diameter. In R. protensa, a native of New Guinea and 
adjacent regions, the initial becomes covered with a greater quantity of gelati- 
nous material than in R. flaccida. As the gemma increases in size it finally 
bursts through the gelatinous covering, which then clings to the base like a 
collar. 
The gemmae of Radula are arranged in two groups according to complexity. 
In the first group the gemmae occur on margins of leaves, are irregular in out- 
line when mature, and may be more than one cell thick; in the second they 
occur on the margin and surface of leaves, are regular in development and sym- 
metrical in form, and are only one cell thick. R. flaccida and R. protensa 
belong to the second class.—W. J. G. LAND. 
Cytology of Hymenomycetes.—Levine,* working in Harper’s laboratory, 
has secured some spore germination (none of the spores of Boletus germinated), 
so that his observations of the nuclear phenomena are somewhat extensive. The 
rmina 
cultures 48 hours old the cells of the mycelium are multinucleate; but in cultures 
3 days old, both uninucleate and binucleate cells are found. The mycelial cells 
of many species are binucleate, with clamp connections, etc. In the mature stipe 
of Boletus granulatus all the cells are multinucleate; while those of the ring, of 
the flesh and trama, and of the subhymenium are binucleate. At the end of the 
second division of the fusion nucleus in the basidium, the centrosomes become 
attached to the walls of the basidium and the 4 daughter nuclei remain connected 
with them by fibrillar strands. The centrosomes determine the points of origin 
uninucleate at first. The conclusion is that an alternation of generations “com- 
parable to that in the Uredineae” is also present in these forms. ‘The sporo- 
phyte begins at some indefinite point in the mycelium and extends through the 
development of the carpophore.”—J. M. C 
Aluminium salts.—FLurt has claimed that aluminium salts render certain 
plant cells incapable of being plasmolyzed by ordinary plasmolytic agents by 
rendering the protoplasm highly permeable to these reagents. Sztics‘ finds that 
the protoplasm is rendered less permeable to many agents by aluminium salts, 

’ LEVINE, MICHAEL, Studies in the cytology of the Hymenomycetes, especially 
the Boleti.. Bull. Torr. Bot. Club 40:137-181. pls. 4-8. 1913 
“ Bor. Gaz, 473252. 1900. 
4s Szics, Josern, Uber einige REE aso des Aluminiumions auf das 
Protoplasma, Jahrb. Wiss. Bot. 52: 269-332. 
