Igt1| CURRENT LITERATURE rh 
The largest number of hybrids secured in any one year were 6, produced in 
1898. It is disappointing to the hybridologist to find in this list almost no 
data of any scientific significance regarding these hybrids. The brief com- 
ments made in connection with each cross refer purely to the value of the 
result for decorative or other economic purposes, and no definite comparison 
ismade between the characters of the hybrid and those of its penn except 
occasionally in regard to cultural matters.—Gero. H. SHULL 
Position of Gnetales.—LIGNIER and TisoNn*s have applied their anatomical 
methods to the so-called “flower” of the Gnetales, bine have reached the 
conclusion that the group belongs to angiosperms, among the koe 
and that it probably represents a reduction series pe from the “base 
the angiosperm trunk.’ This carries one back to the old conflict over gym- 
nospermy; and in fact the interpretation of the ovule of Gnetales is almost 
identical with that of the ovule of gymnosperms nearly 100 years ago, for it 
reads ‘‘un ovaire fermé, protonge en style et stigmate et ne renfermant qu’un 
seul ovule réduit au nucelle.”” This conclusion is a good illustration of the 
use of selected testimony rather than of all available testimony; an eclectic 
rather than a synthetic judgment. One might imagine a reduction series 
resulting in an open ovary, for’there are open ovaries among angiosperms; 
but that such a series could result in the reappearance of such structures as 
archegonia, etc., is beyond the reach even of scientific imagination.—J. M. C. 
Cytase and cytocoagulase.—Griiss* continues his studies upon gum-forma- 
tion in the cherry and peach. He attributes it to the action of cytase upon 
the hemicellulose (especially galactans) of the secondary layer of wood vessels. 
Quantitative analysis shows 4 per cent of the wood vessels to be galactans. 
Excessive gumming he attributes to abnormally high cytase action. In the 
spring, when there is a general digestion of the reserved materials, he could 
detect a dissolution of the setondary layers of the wood vessels in the neigh- 
borhood of the cambium. Cytase was also abundant in this region and the 
vessels were filled with gum. In autumn he finds in the cambium region an 
enzyme which deposits an insoluble product from the gum, which gives the 
reactions of hemicellulose; he calls this condensing enzyme “cytocoagulase.”” 
The papers of Griiss are thrown together in such a way that careful perusal 
leaves one in doubt as to his exact meaning.—WILLIAM CROCKER. 
Germination.—GASSNER” continues his studies on the germination of the 
South American grasses, the present paper reporting on Stenotaphrum gla- 
48 LIGNIER, O., et Tison, A., Les — sont des Angiospermes apétales. 
Compt. Rend. Acad. Sci. Paris 152: 201-204. IQII. 
6 Griiss, J., Ueber das Verhalten von ee und Cytokoagulase bei Gummibil- 
_ Jahrb. Wiss. Bot. 4'7:395-430. 1910. 
27 GassNER, Gustav, Ueber Keimungsbedingungen Sal stidamerikanischer 
Gramineensamen. Ber. Deutsch, Bot. Gesell. 28: 504-512. 1910 
