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1902] CURRENT LITERATURE 75 
continues to enlarge for a long time after fertilization. The chromosomes 
are very long, the gametophyte number being six, the smallest number yet 
reported in seed-plants.—W. J. G. LAND 
INVESTIGATIONS dealing with the influence of the medium on plant 
development continue to multiply. Pethybridge’” has experimented with 
various salt solutions on the development of wheat, finding that the dilution 
of nutrient solutions or the addition to them of NaCl causes root elongation, 
decrease in leaves, shoots, and root diameter, and increase in the thickness of 
endodermis walls; the stomata on the under leaf surface almost wholly dis- 
appear. Root hair formation is repressed in NaCl solutions and in increased 
light. Arker* finds that the rapidity of growth of the roots of Lupinus albus 
is facilitated by introducing air currents, especially if somewhat rarefied, into 
medium. Beauverie™ found that an increase of osmotic pressure caused 
a reduction in the aerial portions of fungi, together with a lateral dilatation of 
the cells; in very strong solutions the entire plant often became submerged. 
A more recent study of various seed plants has yielded similar results. 
Beauverie refers the well known root curvature in water to differences in 
Osmotic pressure rather than to aerotropism, finding that the roots grow 
straight down in concentrated solutions. The aerial axis becomes reduced in 
height and broadened laterally as in fungi. The anatomical structure is 
affected also; a thick cork layer is developed very early in strong solutions ; 
but this is not the case where the pressure is weak.— H. C. COWLES. 
BERNARD” has presented to the Paris Academy of Sciences two papers 
ch will be certain to incite interest and further investigation. In the first 
Paper, entitled precocious tuberculization in plants, he recalls the production 
‘tubercles on legume roots and coralloid processes on various tree roots 
through stimulation by bacteria and fungi. Bernard shows the remarkable 
resemblance between the tuberculous organs of lycopods and orchids, two 
wiely Separated families. The gametophyte and sporophyte of Lycopo- 
ges and the sporophyte of several orchids show essentially similar organs, — 
and are infested by similar fungi, and in all cases the fungus is Fusarium or 
: related form. Of a large number of tuberous plants investigated by Stahl 
in his recent mycorhiza studies, Corydalis alone is found to be without fungi. 
— Second paper Bernard makes the surprising statement that it is his 
Meter — the tubers of the potato are essentially galls and due to fungus 
eas aie He Shows that Fusarium Solani is always present in the tubers, 
wet seems likely that this fungus causes the arrest of the terminal bud and 
7 Inaugural dissertation. Géttingen. 1899. (See Bot. Centralb. 87 :235- 1901-) 
- 1; ee coe <— oo 
_™ Inaugural dissertation. Erlangen. 1900. (See Bot. Centralb. 87: 235. 1g0t.) ae 
“Compt. Rend. 132: 226-9. 1901. _ 
nC : & : i : 
: "Compt. Rend. 131: 626-629. 1900; 132: 355-357- 1901. 
