1896. ] Anatomical and Physiological Researches. 161 
vature. According to the results of Noll’s recent researches 
it seems somewhat conclusively demonstrated that the stimu- 
lus induces an increased plastic and elastic extensibility of 
plasm, that these membranes extend in length from the pres- 
sure of turgidity, which is equal throughout the entire cross 
section, but the membranes of the concave side are unaltered 
and do not respond farther to it. That the extension of the 
membranes of he convex sides is not growth is shown by the fact 
adduced by Noll that they not only become thinner during 
the extension but do not increase in dry weight. The altera- 
tended wall and prevents the reflexion of the old curvatures 
to the initial stature of the organ when plasmolysed.—D. T. 
Mac Dougat. 
Selection of organic foods by plants. 
quantity sufficient to completely satisfy the demand for this 
f 
tion takes Place, to what degree does it occur 
he experiments were conducted exclusively with the 
lower fungi, in most cases with Aspergillus niger and Penictl- 
"um glaucum. In the first series of experiments, two car- 
bon-containing Compounds of rather unequal nutrient value, 
dextrose and glycerine, were added to the nutrient solution in 
various Proportions and the fungi in pure cultures were culti- 
Yated therein, The general result was that a choice was ex- 
Roe in taking up the necessary carbon-containing material. 
oth were somewhat used, but the better food, the dextrose, 
Bo TEPPER, W.: Ueber Election organischer Nahrstoffe. Jahrb. f. wissensch. 
* 28: 205. 1895, 
