1g12| CURRENT LITERATURE 265 
he has failed to find a single one without living tenants. These larvae have 
been reared and studied by MEIJERE,” who describes 7 species, of which 6 are 
new. They are to be referred to the order Diptera, and belong to three different 
families. 
Not the least remarkable characteristic of these larvae is the power they 
seem to possess of anti-fermentation, and which appears to retard the action 
of the enzymes of the fluid filling the pitchers. Experiments upon their 
influence upon the action of solutions of pepsin and pancreatin furnish 
evidence of their retarding influence. Closely related larvae, taken from pools 
in the vicinity, were unable to live in the pitchers; hence the anti-ferment is 
regarded as an adaptation to such symbiotic existence.-—GEO D. FULLER. 
Grape mildew.—A number of infection experiments, bringing out some of 
the relations between the downy mildew of the grape and its host, have been 
described by MULLER-TuHuRGAU.” Pot-grown grapevines were brought into 
a greenhouse, and only the new shoots that developed under glass were used 
for the experiments. The infected shoots were covered for a time with glass 
cases, to prevent too rapid evaporation of the drops of water containing the 
spores used for inoculation. The main results of the experiments are the 
following: No infection took place on the upper surface of the leaves unless 
punctures had been made in the epidermis. Infections took place readily on 
the lower surface if the plants were kept in a moist atmosphere. The very 
youngest leaves were not readily infected, a fact which the author attributes to 
causes within the leaf rather than to such outer factors as the dense hairy 
covering. Leaves a little older are _ easily infected and in these the 
fungus grows a long time and form ts of considerable size before the infected 
area dies. On the older leaves ‘ina action of the fungus is more severe. The 
infected spots remain small, u 3-5 mm. in diameter, but the tissue 
of oospores are found. The difference in behavior of leaves of different ages 
is attributed to differences in moisture content or to differences in composition. 
—H. HASsELBRING. 
Egg-formation in Cystosira and Sargassum.—NIENBURG” reports the 
result of his investigation on the development of the eggs of Cystosira and 
Sargassum. Cystosira barbata Ag. was collected at Naples in the spring of 
1907, and Sargassum linifolium was obtained from Triest in September of the 
following year. The paper presents briefly the nuclear divisions in the oogo- 
nium of Cystosira and the development of sporelings of Sargassum. The author 
“Mxyesz, J. C. H. px, ee I. Systematik. Ann. Jard. Bot. 
Buitenzorg cae 3. pt. 2. 917-940. 1910 
MU rer-Tuurcav, H., yng = Weinrebe durch Plasmopara viticola. 
Cental Bakt. ia 29: 683-695. fig. I. 
* NIENBURG, WILHELM, Die Oogonent kn bei Cystosira and Sargassum. 
Flora 1: iia, pls. 2. fiss: 0: 
