34Q 



BOTANICAL GAZETTE [aprii. 



tissue containing the enzyme in a small amount of glycerin and placing this on a 

 filter paper From this mass the water circle spreads and the enzymes can be 

 located at various radial distances from the center. In dealing with oxidases the 

 whole process is performed in an atmosphere of hydrogen. It is not evident 

 that this method is of any great value further than as a mere means of demon- 

 strating the presence of certain enzymes. Gruss also claims hy it to gain evidence 

 that cytase is not distinct from diastase, and believes he has shown in a number 

 of other cases that a single enzyme performs several catalytic functions. His 

 arguments against the specificity of enzymes are to a degree plausible, but are far 



from conclusive. 



Gruss also asserts, 8 on the basis of considerable experimental evidence, 

 that the reducing power of fermenting yeast attributed to the action of reductase 

 can be accounted for by the nascent hydrogen set free by the hydrogenase of the 

 yeast. In the presence of fermenting yeast the reduction of sodium seleniate 

 and sulfur occur as they do when treated with nascent hydrogen. He finds no 

 evidence for postulating reductase in yeast. He believes that the fangi in general 

 possess hydrogenase and not reductase. If this be true the reductions came 

 on by this group of plants are strikingly similar to the simplest reductions in t e 

 chemical laboratory. He agrees that yeast and other fungi show a very s igb 

 reducing power not due to hydrogenase, but the substance that produces t is 

 slight reduction shows none of the characteristics of an enzyme— Wm. Crocke l 



Germination in Rhinanthaceae — Sperlich<> believes he has den J onb ^ m 

 that the germination of the seeds of the partially parasitic species, ^'"j^ 

 silvaticum, M. arvense, and Alectorolophus hirsutus, is greatly hastene ^ ^ 

 presence of the host plant. These seeds show a considerable rest peno an ^ 

 concludes that the favorable action of the host is evident only up to the f^^ 

 of the " after-ripening." A close examination of his data shows that i^co 

 sions do not necessarily follow from them. He always gets a very' °* 



germination 



variations in results from similar cultures. 



indicates the presence of some uncontrolled factor. On discussing ^^ 



ing" he makes no mention of the general connection of delayed an 



:ermi nation 



charac 

 One 



ters. He apparently has no knowledge of the literature on the su j^ ^ 

 wonders if his results are not merely the measurement of seed-coa e ^ ^ ^ 

 certainly has not demonstrated dormancy in the embryo itself, w ' ^ Q ernian 

 step in establishing his main position. "* " *——••*'- " f a number ° 

 investigators to refer the phenomena of "after-ripening to lllt ". v "" of th 

 protoplasm is to be deplored, especially when a thorough examination^ ^^ 

 will often furnish a very simple explanation. It must not be forgo 



The disposition of a numwi u 



"after-ripe^" to the *£~* 



8 Gruss, J., Hydrogenase oder Reduktase? Idem: 627-630. iQ° • 

 * Sperlich, Adolph, 1st bei griinen Rhinanthaceen ein *° D e utsch. 



Organismus ausgehender ausserer Keimungsreiz nachweisbar . 



Geselh 26a: 574-587. 1908. 



lichen 

 Bot. 



