1913] CURRENT LITERATURE 167 
disappears, so that the four nuclei come to lie in a single cell. The upper and 
lower ends of this cell are cut off as the “restored trichophoric cell” and the 
inferior supporting cell. Each of these contains a single nucleus. The two 
remaining nuclei undergo a series of conjugate divisions, as a result of which a 
superior supporting cell, and sometimes a secondary inferior supporting cell, 
each with two nuclei, are cut off. Two nuclei, presumably one derived from 
each nucleus of the original pair, remain in the parent cell or ascogonium. 
e ascogonium may either give rise to asci directly, thus itself becoming an 
ascogenous cell, or it may divide and give rise to two ascogenous cells. The 
only nuclear fusion in the life cycle of the plant is that which takes “peg in 
the ascus.—H. HassELBRING. 
Mitochondria.—The literature on mitochondria is growing, but as : 
grows the difficulty in defining the structures becomes greater and greate 
Just as centrosomes were followed by centrosome-like bodies and les iiaspohcats 
by blepharoplastoids, the mitochondria are now followed by mitochopdria- 
like structures. Woycicxr's describes in the pollen mother cells and micro- 
spores of Malva silvestris mitochondria-like bodies, which first appear as small 
granules, then become vacuolate and divide by constriction, and finally dis- 
appear completely after the formation of the intine. Starch is entirely lacking 
during these stages, starch grains first appearing after the exine has become 
differentiated. e mitochondria-like bodies have nothing to do with leuco- 
plasts or the formation of starch. In Malva they resemble somewhat the 
proteid vacuoles of Coniferales. 
mprovements in technic have certainly brought to light some minute 
structures of the cell which were previously overlooked, but what these struc- 
tures are and what their significance may be, are problems still awaiting 
solution.—CHARLES J. CHAMBERLAIN. 
Wilting coefficient in alkali soils.—In a series of 14 alkali soils, gradu- 
ated according to their salt content, KEARNEY has shown the wilting 
coefficients to be practically identical, but the time required for the exhaustion 
of the water available for growth steadily increased with the increasing salt 
content. The plants were proportionately smaller when the wilting coefficient 
was reached in the soils of greater salt content, that is, the presence of 
alkali increased the quantity of water transpired in producing a unit weight 
of dry matter. With too great a quantity of salts, pathological conditions 
were evident in the plants and the wilting coefficient was not reached.—Geo. D. 
FULLER. 

*s Wovcicxt, Z., Uber die mitochondrieninliche Gebilde in den Gonotokonten 
und Gonen bei Malva silvestris L. Sitzungsber. Warschauer Gesell. Wiss. 5:167-182. 
pls. 1, 2. 1912. 
© KEARNEY, THomas H., The wilting coefficient for plants in alkali soils. Bur. 
Pl. Ind. Circ. 109. pp. 9. 1913 
