1887. ] BOTANICAL GAZETTE. 155 
Fig. 3 shows a series of ten cells immediately adjoining 
the cut, and illustrates fairly well all the points indicated 
above. In all the figures the cut is at the left, and the 
darker shading represents the apparent centers. 
series of experiments made in January and February 
verified the results upon which the paper was based. The 
ou of other shocks was then tried, with the following re- 
Sults : 
Filaments plunged into boiling water showed a large dis- 
tension of the cell, accompanied by disintegration and diffu- 
sion of the band; a result presumably caused by the expan- 
sion of the cell contents by the heat, although possibly the 
water may have penetrated the cell walls. 
_ Filaments were then frozen in water by an improvised 
ice-cream freezer, and were kept packed in ice for twenty- 
four hours. No change was shown, if we except the evident 
checking of all vegetative processes. It is possible that a 
greater degree of cold might have produced different results. 
ilaments were also subjected to an electric shock ; but 
In every case, even with the feeblest current I was able to 
secure, the result was the utter destruction of the filament. 
Filaments were then subjected to the action of various 
dilute acids. In all these cases the entire protoplasmic con- 
tents of the cell were contracted, involving, of course, the 
band. Brine gave similar results. In none of the cases was 
there even an approach to the forms shown above except In 
the case of brine, which, when very strong, would sometimes 
vive forms resembling those shown in cells 7,8 and 9 of Fig. 
evidently Spirogyra quinina, surprised me by failing to re- 
mes to laceration as readily and uniformly as I could ge 
© band was more wrinkled, abounded in nodules, an 
