76 
Walter Gardiner. 
raenced to investigate in as complete a manner as possible the phenomena 
attending Plasmolysis. It bad been long known that wlien living cells are 
exposed to the action of some strong dehydratiDg agent such as dilute acids, 
dilute Chlor. Zinc. Jod., strong sugar or salt Solutions, the protoplasm often 
appeared to separate with difticulty from the cell-wall, or was held on to 
the wall at certain points by fairly thick protoplasmic processes. Thus von 
Mohl ') had remarked that upon treatmeut with acids his primordial utricle 
adheredto the cell-wall, 1 2 ) Pringsheim in Fern prothalli, in Riccia, Vallisneria 
and Cladophora also remarked that the protoplasm after treatmeut with 
dilute Chlor. Zinc. Jod. or strong sugar solution, separated with difticulty 
from the cell-wall and was often drawn out into Strands which still clunu 
to that structure. Nägeli, 3 ) and also Hofmeister 4 ) in the case of Spirogyra, 
and various (ilamentous algae established the same fact. But after such 
treatmeut the protoplasm is gravely afifected, often appearing partially coa- 
gulated as il were, and subsequently dies. It w as Hugo de Viues 5 6 ) however 
who most fully investigated the action of dehydrating agents on the living 
cell, and by his important results materially increased our knowledge of 
general cell meehanics. He employed only dilute Solutions of such a strength 
that while they brought aboul the condition of Plasmolysis, they exercised 
but little hurtful influence on the protoplasm itself. This observer found 
that w’hen living cells are treated with progressive!} stronger Solutions of 
some neutral salt e. g. 4, 6, and 10 per cent of nitre, the protoplasm shrinks 
from the cell-wall unlil at length it appears as a much contracted spherical 
mass lying freely in the cell cavity. But in repeating de Yuies’ experiments 
I found/’) in everv instance I examined, that the contracted primordial utricle 
does not lie free but is always connected to the cell-w all by innumerable 
fine protoplasmic strings. This discovery was also subsequently and in- 
dependently confirmed by Bower 7 ) w ho w as experimenting on plasmolysis 
for a very different object, namely that of fiuding whelher the inducing of a 
plasmolytic contraction of the protoplasmic body would be a good method 
for preparing the apical region of the prothallus, so as to show the form and 
arrangement of the individual cells. 
I employed as dehydrating agents Solutions of common salt of the 
followdng strengths viz. 2.5 p. c., 5 p. c. and 10 p. c. amH was able to de- 
monstrate not only that by the action of strong Solutions the protoplasm 
suflers apparent partial coagulation, separates with difticulty from the cell- 
1) von Mohl. Vegotable cell. English translation. p. 37. 
2 ) Pringsheim. Bau und Bildung der Pflanzenzelle. 1834. 
3t Nagelt. Pflanzenphysiologische Untersuchungen, 1883. Heft I. 
4) Hofmeister. Die Pflanzenzelle, 1867 . 
5) II. de V ries. Unters, ü. die mechanischen Ursachen der Zollstreckung. Leipzig 1877. 
6) Gardine«. Royal Society Proceedings. Nov. 11 . 1882 . 
7) Bower. Quart. Journ. Micr. Sei. Jan. 1883. 
