1904] CURRENT LITERATURE 225 
formation of the pollen is normal, a reduction in the number of chromosomes 
taking place in the pollen mother-cells. In the formation of the megaspore in 
some cases a tetrad of four megaspores is formed, accompanied by a reduction 
in the number of chromosomes. In other cases no reduction takes place in the 
megaspore mother-cells, and sometimes a true tetrad is not formed. Such con- 
ditions are not unexpected, since OvEeRToN had previously shown that while 
Thalictrum is often parthenogenetic fertilization may occur. The number of 
chromosomes in the sporophyte is twenty-four and in the gametophyte twelve. 
—Cnartes J. CHAMBERLAIN. 
PARTHENOGENESIS in Gnefum Ula Brogn. is reported by Lotsy.'5 In the 
development of the female gametophyte, as in G. Gnemon, a period of free 
nuclear division is followed by a period of cell formation. ‘The cells of the lower 
part of the gametophyte are small and form a close tissue, while in the upper 
part they are much larger and are loosely associated. No pollen tubes were 
observed, but many of the loose cells in the upper part of the gametophyte behaved 
like zygotes, sending out tubes as described for other species of Gnetum. The 
number of cells behaving in this way was so large that the pollen tubes could 
scarcely have been overlooked had they been present. This study has strength- 
ened Lorsy in his previous view that the angiosperms have not come from the 
Gnetaceae—CHaARLES J. CHAMBERLAIN. 
CARLETON" has published a series of notes giving the results of investigations 
and culture experiments with rusts. Tt is found that Uromy es euphorbiae can 
be propagated through the agency of seeds and seed pods infected with the fungus. 
bes the first instance of a rust propagated in this manner. A long series of 
*xperiments with the black stem rust of Agropyron and Elymus showed that 
this rust could be transferred to a number of hosts, including wheat, barley, 
» Agropyron tenerum, A. Richardsoni, Elymus canadensis; while 
writer in a former paper, that the uredo of the orange leaf 
he winter, is again emphasized in this discussion. It is also 
o of blue grass rust is hardy.—H. HaAssELBRING. 
THE Fact that copper sul 
than upon animals is taken ady 
for killing algae, etc. 
Water injurious for 
€xterminated, to the 
—wt Poison ‘is add 
pls, Ph ig i. - P., Parthenogenesis bei Gnetum Ula Brogn. Flora 92: pedals 
fate is much more toxic in its effect upon plants 
antage of by Moore and KELLERMAN’? in a method 
, in reservoirs, without at the the same time rendering the 
human consumption. According to the organisms to be 
flow of the water, and other conditions, a certain amount 
ed to the reservoir, a device being used to insure uniform 
16 ‘ 
Indus om. M. A., Investigations of rusts. U.S. Dept. of Argic. Bur. Pl. 
: - 63. pp. 29. pls. 2. 1904. 
the Shesig ey G. T., and KELLERMAN, K. F., A method of destroying or preventing 
of Agric. B algae and certain pathogenic bacteria in water supplies. U.S. Dept. 
* Sur. Pl. Indus. Bull. 64. pp. 44. 1904. 
