Physiologie. 139 



brought forward by himself and Joiy in 1894. Stelnbrinck 

 has recently shown that cell-walls in all conditions of lignification, 

 Saturation by water etc. are to a considerable extent permeable 

 to air under a difference of pressure of less than one atmo- 

 sphere and as a result of this contends tiiat the cohesion theory 

 of Dixon and Joly is untenable. The author claims that Stein- 

 brinck's discovery is not antagonistic to his views. Water 

 containing iarge quantities of alr is as capable of transmitting 

 tension as air-free water. Consequently air, diffusing through 

 the moist lignified walls of the conducting capillaries, neces- 

 sarily being in Solution, would not break, or tend to break, the 

 continuity of the water-columns within them. He shows that 

 only if undissolved gas could pass into the cavities of the 

 capillary vessels through the walls could the water in them 

 be rendered incapable of withstandig tension. Even if such gas 

 found its way into one of the vessels or tracheids it can 

 only throw the lumen of that particular unit out of function, for 

 the free gas of the bubble formed therein cannot pass through the 

 cell walls, but is confined within the compartment where it was 

 formed. The current is consequently only deviated from that 

 one Clement of the wood in which the rupture in the watery 

 column has occurred. The second criticism to which the author 

 replies was advanced by Copeland last year and was based 

 upon experiments made by himself on the ascent of water 

 through tubes containing moist plaster of Paris. He shows 

 these to be fallacious based as they are on the assumption 

 that the properties of plaster of Paris are comparable with 

 those of wood. The resistance offered by the plaster to the 

 passage of water through it is at least 13 times as great as that 

 of wood. A further very important disturbing cause is that 

 on setting, even when an excess of water is present, plaster of 

 Paris does not take up the füll amount of water it is capable 

 of absorbing but continues steadily to do so, long after setting 

 is complete. Reynolds Green. 



Emmerling, 0., Oxalsäurebildung durch Schimmel- 

 pilze. (Centralblatt für Bakteriologie. 11. 1903. Band X. 

 p. 273.) 



Untersuchungen an Aspergillus niger lieferten das Er- 

 gebniss, dass, unter Beigabe von Ammonsulfat als Stickstoff- 

 quelle und von Nährsalzen, die verschiedensten Kohlenhydrate 

 (Glukose, Laevulose, Maltose, Saccharose, Galaktose, Laktose^ 

 Raffinose, Trehalose, Stärke, Glykogen, Xylose, Arabinose), die 

 höheren Alcohole (Glycerin, Erythrit, Dulcit, Mannit) und nicht 

 amidirte Säuren (Aepfel-, Wein-, Bernstein-, Milchsäure) trotz 

 lebhaften Wachstums nicht Anlass gaben zur Bildung von 

 Oxalsäure. Sehr verschieden gestaltete sich das Verhältniss bei 

 Amiden, Aminosäuren und Eiweisskörpern : Leucin, Phenyl- 

 alanin, Harnstoff, Methylaminchlorhydrat, Aethylendiaminchlor- 

 hydrat, BetaYn und Oxypiperidon gaben gar keine bis kümmer- 



