294 The Botanical Gazette. [May, 
the characteristic action of the agent from the reaction due to 
the sudden change of conditions. Great variability is to be 
expected not only according to the plant, but even among like 
cells of the same plant, and at different times and under differ- 
ent circumstances. 
The symptoms of death are in most cases distinct enough, 
but in doubtful cases death was determined by the incapa- 
bility of contraction on the addition of a plasmolyzing solu- 
tion, or by the capacity to accumulate coloring matter, which 
appears only at death. Nigrosin, which is entirely harmless, 
was chiefly used for this test. 
As dynamic agents Klemm used high and low tempera- 
tures, light, and electricity. As material reagents he used 
inorganic and organic acids, alkalies and alkaloids, H, 0, 
CuSO,, FeSO,, alcohol, phenol, and anilin colors. 
As experimental material, that specially rich in protoplasm 
proved most serviceable, such as plasmodia of Myxomycetes, 
stamen-hairs of Tradescantia, cells of Spirogyra, filaments of 
Vaucheria and some marine Siphonee, hyphz of Saprolegnia, 
end the root hairs of Trianea Bogotensis, which are finely 
adapted to the action of material agents because not cuticu: 
larized. A 
the 
Previous observations mainly agree as to of 
n 
1. Heat. é 
visible alterations from high temperatures, viz., cessation 
movement, rigor, and eventually aggregation or separation 
of masses of protoplasm. Klemm used Pfeffer’s warm stage 
and determined, first, that gradual heating can be carried 
a degree at which its sudden application is immediately fatal. 
Under these circumstances the alterations affect the mov 
: 8 ‘ 
higher temperature the streaming was slowed with often trem 
ulous movements of the plasma strands. This was s¥ 
by the formation of clumps here and there, and later by rigof 
Hairs of Momordica and Tradescantia could be heated 
the wall followed, but when heat was applied sudden 
Whe 
