220 BOTANICAL GAZETTE [MARCH 
All curvatures, especially the S-ones, are parallel with traumatropic curva- 
tures. GASSNER rejects BRUNCHORST’s explanation (the action of the products 
of electrolysis, to which in essence SCHELLENBERG adheres) and that of RISCHAWI 
(accumulation of water on the convex side), claiming that galvanotropism is only 
a special case of traumatropism, in which the injury to the positive side is prob- 
ably wrought by the passage of the current, as happens with other semipermeable 
membranes. Admitting that the electric current probably produces its effects by 
reason of migration of ions, GASSNER definitely declines to identify galvanotropism 
with chemotropism, since the latter itself may be only a modified form of trau- 
matropism or indeed of osmotropism. Nor does he think the entry of hydroxyl 
ions on the anode side can account sufficiently for the injury, because by calcu- 
lation their amount is infinitely small, and in an experiment rootlets of corn, 
containing red anthocyan, showed no change of color, though they curved well 
in a strong current. Rather he would ascribe the injury to the emigration of 
ions from the plasma 
The “observations i in ne sot papers are not so wide oo nor are the 
g they at first appear.—C. R 
i) 
Paleozoic botany.—In his presentation of the present status of paleozoic 
botany, Scorr’4 dismisses the lower cryptogams with the brief space (7 pages) 
which their recorded occurrence in the paleozoic strata warrants, and devotes the 
remainder of his article to the Vasculares. He adopts provisionally the division 
of vascular plants into two phyla, the Lycopsida and the Pteropsida, as propose 
by Jerrrey. Under the Lycopsida are ranged the following classes: Spheno- 
phyllales, Equisetales, Psilotales, and Lycopodiales. e first two classes are 
included under a group name, Articulatae, a propinquity of relationship thus 
being recognized, which was first pointed out by JEFFREY and subsequently by 
Licnter. In his treatment of the Sphenophyllales the author describes the 
features of the various types, already for the most part generally known from 
his textbook. One genus new to the general student is NatHorst’s Pseudo- 
bornia from the Upper Devonian of Bear Island, which is regarded by its author 
as the type of a special class, the Pseudoborniales. It is characterized by highly 
dichotomously divided and pinnatifid leaves, which have a certain resemblance 
to fern-fronds, a resemblance which is considered by Scorr as of sufficient impor- 
tance to indicate a certain affinity between the sphenophyllaceous stock and that 
of the Filicales. Unfortunately nothing is yet known of the internal structure of 
Pseudobornia. The author regards the characters of Psilotum and Tmesipteris 
as sufficiently distinct from those of the Lycopodiales to warrant their separation 
as a special class, the Psilotales. Indeed, he is of the opinion that their peculiar 
sporophylls find their nearest counterpart in those of the  Spbenophyiinies. The 
author even states that if he had to choose between | phyl 
laceous antecedents for his new class he would chose the latter. 
as Scott, D. H., The present position of paleozoic botany. Progressus Rei Botan- 
icae, redigiert von J. P. Lotsy, pp. 139-217. 1906. 
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