480 BOTANICAL GAZETTE ._ [DECEMBER 
It is found that when a race of cotton is introduced into a new locality it 
usually shows at once an epidemic of variation in tats directions, many of the 
plants showing a large amount of deterioration. The tendency can be eradicated 
only by selecting from the best (unmodified) ee in the new locality. 
In this manner a reasonab y constant race is finally obtained in the new locality, 
the process being known as local adjustment. New-place diversity is thus a 
phenomenon distinct from ordinary fluctuating variability, and of prime impor- 
tance in connection with acclimatization. These new-place variations are not 
adaptations to the conditions, but are considered to be ‘‘experiments in accommo- 
dation” or as “‘affording the materials from which the more definitely accommoda- 
tive characters may be developed.”’ Neither are they directly impressed upon the 
plants by the external conditions, but much of the diversity is believed to represent 
“transmitted characters which have been able to come back into expression because 
the change of conditions has disturbed the previous adjustments that selection had 
established.”—R. R. 
Plants with HCN.—MrranpeE finds’? that green plants which contain 
cyanic compounds, if subjected to the action of chloroform, ether, and other vapors 
that check photosynthesis, exhale a strong odor of hydrocyanic acid. He proposes 
therefore to use GUIGNARD’s test3® in connection with this process to determine 
what plants contain such compounds. The test requires only a short time and 
avoids all the complicated and troublesome processes necessary for chemical 
analysis. Besides it seems to be more delicate and certain. Thus MIRANDE 
seit that the presence of hydrocyanic acid may readily be detected in Arum 
maculatum, a plant in which the existence of HCN, long in controversy, has lately 
been ae by analysis.—C. R. B. 
Geotropism and metabolism.—The only experiments which have claimed to 
show a direct connection between irritability and metabolism have been those of 
CzaprexK and BErTEL, who found that in geotropically stimulated roots there was 
an accumulation of reducing substance, which they identified as homogenistic 
acid. The precise character of this substance has been controverted. Now come s 
Grare and LinsBAvER,?? who report that in the material used by them (Lupinus 
albus and Vicia Faba) the absolute amount of reducing substances (character 
not determined) is very small and far below the values found by CZAPEK. More- 
over, there was no constant difference between the stimulated and the unstimulated 
roots.—C. R. B. 
MrRanDE, M., Influence exercée par certaines vapeurs sur la cyanogénése végé- 
tale. ead rapide pour la recherche des plantes A acide cyanhydrique. Compt. 
Rend. Acad. Sci. Paris 149:140-142. Ig09. _ 
38 Bot. GAZETTE 43:288. 1907. 
x0 Grare, V., AND Linsnaver, K., Zur Kenntnis der Stoffwechselnderungen bei 
geotropischer Reizung. Sitzb. K. Akad, Wiss. Wien Math.-nat. Kl. 118:907-916. 
1909. 
