78 BOTANICAL GAZETTE [JULY 
Proteases.—VINES,?3 in continuing his work on the proteolytic enzymes of 
plants, finds that both malt extract and taka-diastase (Parke Davis and Co.) 
contain enzymes capable of digesting fibrin and of splitting peptone. From malt 
extract he has isolated the peptone-splitting enzyme free from the fibrin- ig 
body, and from taka-diastase he separated each from the other. Both thes 
enzymes seem to act best in acid media. In animal tissues there are two Pris 
splitting enzymes: a protease, weak and acting in basic media; and £ protease, 
more powerful and acting in acid media. By special methods of preparation, 
VinEs obtained a protease which acted best in neutral and basic media. This 
perhaps corresponds to the a protease of animal tissues. The ereptases, peptone- 
splitting enzymes, of animal tissues act best in basic media. VINES’s work shows _ 
that plant ereptases act in acid media. As to terminology, one is aed to 
believe that VINEs could —_ profitably that of animal workers as given by 
VERNON. ?4—WILLIAM CROCKE 
A new genus of Cordaitales.—Scorr and MAsLEeNn?’ have described a new 
genus (Mesoxylon) of Cordaitales from the calcareous nodules of the Lower 
Coal-measures of Lancashire. It is intermediate between Poroxylon and Cor- 
daites, as its name implies, including five species which have been referred here- 
tofore to these two genera. e combination of characters is the anatomical 
habit of Cordaites and the centripetal xylem of Poroxylon. The pith is rela- 
tively large and discoid (as in Cordaites); the wood is dense, with narrow pith 
rays and relatively small tracheids; the leaf traces are double, but divide before 
entering the leaf; the centripetal xylem is present in the leaf traces at the margin 
of the pith (as in Poroxylon) and throughout their course to the leaves. The 
genus is thought “to completely bridge the gap, so far as anatomy is concerned, 
between the Poroxyleae and the Cordaiteae,” and helps to connect the cordaitean 
and later forms (excepting cycadophytes) with the “pteridosperms.’’—J. M. C 
‘‘Bars of Sanio” in Coniferales.— The “‘bars of Sanio” are “‘folds”’ of cellulose 
to be observed in the walls of tracheids as horizontal or more or less semnicirenes 
markings, which stand out clearly with proper staining. Miss GERRy’° h 
investigated their distribution among the Coniferales, and has discovered that 
they furnish a constant and useful character in the determination of fossil woods. 
They were found in 35 of the living genera, but do not occur in Agathis an 
Araucaria, nor in the mesozoic araucarians. Since they do occur in the podo- 
carps, it is concluded that this group is more closely related to the Abietineae than 
to the Araucarineae, a conclusion which contradicts a growing conviction bas 
23 VINES, S. H., Proteases of plants. Annals of Botany 24:213-222. 1910. 
24 VERNON, H. M., Intracellular enzymes. London: John Murray. 1908. 
2s Scott, D. H., and Masten, A. J., On oT a new genus of Cordaitales 
ecngres note). Annals of Botany 24:236-239. 1 
26 GeRRy, ELOIsE, The distribution of the i of Sanio” in the Coniferales. 
Annals of Botany 24:119-124. pl. 13. 1910 
