1887. | BOTANICAL GAZETTE. 153 
Spirogyra under shock. 
STANLEY COULTER. 
-At the December meeting of the Indiana Academy of 
Science I presented a paper showing a peculiar action of the 
young chlorophyll band of Sperogyra guéuina Kiitz. under 
shock, which indicated its extreme sensitiveness and very 
considerable tension. The question arose as to whether this 
action was constant, or merely the result of peculiar condi- 
tions. If the latter, what were those conditions: 
The observations upon which the conclusions of the paper 
were based were briefly as follows: : 
ertain vigorous vegetative filaments. being cut with a 
scalpel for the purpose of reducing their Jength, showed that 
the chlorophyll band was broken up in the cells adjacent to 
the cut. This breaking up seemed to have fullowed a some- 
what definite plan. In the culls immediately adjoining the 
cut the band was broken into twice as many parts as there 
Were turns of the band, and these parts were coiled closely 
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about a darker colored center, which appeared in no wise 
different from the nodules. As the distance from the lacera- 
tion increased the closeness of the coil diminished, but the 
number of parts was still double the number of turns in the 
cell. Still further from the cut, instead of the simple Heh 
the:baidt on’ either-sidé of the darker apo’ broke away 
from its surroundings, and showed a marked tendency to 
edi about this «dark spot’ as a center,  In'cells still further 
removed from the wound, while the band was not completely 
broken up, it never failed to show a strong tendency on the 
Part of certain regions of the band to gather about certain 
definite centers, and these centers were always twice the 
number of turns in the cell. However sharp the instrument, 
however deft-the stroke, the chlorophyll band never yori ge 
Tespond to the laceration through from eight to ten Figs 
both ditectione The only peculiarities observed in the spec- 
Imens examined were: 
1. The band rarely, if ever, filled the entire cell length. 
- The edges of the band were entire—not * wrinkled 
and crenulated.”’ 
