478 BOTANICAL GAZETTE [JUNE 
those of the rhizome has been traced. The writers derive the condition seen 
in P, aguilina from the simpler one presented by P. incisa integrifolia, in 
which the infoldings of the petiolar stele are continued down into the rhizome 
as infoldings, while in P. aguzdina the infoldings become sah ie & strands 
in the rhizome.--M. A. CHRYSLER. 
E STIMULATION OF GROWTH by poisons has been studied by Kanda.” 
He finds that seedlings of Pzswm sativum in water culture are not stimulated 
by CuSO, at any concentration. The salt is toxic at a concentration of 
M/1,000,000,000, When these seedlings are grown in water which contains 
traces of ZnSO, they are stimulated to greater growth, the optimum concen- 
tration lying between 4//10,000,000 and 47/1,000,000,000. _ This salt is toxic 
at 47/1,000,000 concentration. In a similar way NaF is found to stimulate 
Pisum seedlings when at a concentration of 54//10,000 to 54//100,000. NaF 
is toxic at about 547/I,0o00 concentration. When grown in pots of soil and 
watered with solutions of CuSO, and ZnSO , seedlings of Vicia Fada and 
Pisum sativum show a marked stimulation at a certain concentration. O 
course the amount of salt cannot here be measured; the fact of stimulation 
alone is noted.—B. E. Livinesron. 
Cc NG TO RESEARCHES OF GRUSS,” it is possible to demonstrate 
in yeast cells, and in a glycerin extract of them, a substance which splits 
free oxygen from such molecules as hydrogen peroxid, potassium perman- 
anate, and the oxidation products of di- and tetramethylparaphenylendiamin 
chlorid, etc. It is possible to destroy the oxidase in yeast by treatment with 
aceton, after which treatment the power to split oxygen from the above 
bodies is still exhibited to a marked degree. The author was able to sepa- 
rate oxidase from this new body (which he terms peroxidase) by their unequal 
rates of diffusion. If into a mixture of yeast cells rubbed up in glycerin 
strips of filter paper are hung, it is found that the peroxidase ascends in the 
paper much faster than does the oxidase, so that the paper at a certain level 
is found to give no reaction for the latter enzyme, while the presence of 
peroxidase was easily scncasliaiel Griiss thinks the new body is probably a 
true enzyme, of opposite action to that of oxidase.— VINGST 
THE NOTABLE LENGTHENING which takes place in the stipe of Taraxacum 
during the ripening of the seed has often been commented upon, especially 
the older ecologists. Miyake** has made daily measurements of the 
growing stipe in numerous specimens of several varieties of Taraxacum. 
22 KANDA, MASAYASU, Studien iiber 7 eens einiger Metallsalze auf das 
Wachsthum were Pfla anzen. Jour. Col i. Imp. Univ. Tokyo 19: [article 13]. 
PP. 37- sot 
ay Pea das Reversionsenzym der Oxydase. Ber. Deutsch. Bot. 
ae ai: ee 903 
24 MIYAKE, K., Ueber das iin des Bliitenschaftes von Taraxacum. Beihefte 
Bot. Sade. 16: 403-414. pi. 7. 
