366 True. — On the Influence of Sudden Changes of 
In experiments with plasmodia of Aethalium septicum , Stahl 
found that sudden changes of medium involving even as slight 
a difference as 0-25 - 0-5 per cent, sugar were sufficient to 
fatally affect those parts of the plasmodia which were in 
contact with the solution. Stahl 1 regarded the results seen 
as complicated phenomena of protoplasmic irritability. 
Experiments involving similar changes of substratum have 
been made with Algae. 
In studying the effects of a rapid increase or decrease of 
the salt-contents of the medium on marine Siphoneae, Noll 2 
found that the turgor-change in a mechanical way could even 
endanger the life of the organism. By suitable change of 
concentration, he found that the turgor-increase could be 
sufficient to rupture the cell-membrane. 
When Fucus was treated in a similar manner, Oltmanns 
found that internal injury was produced, the medium becoming 
discoloured, probably by the colouring matter from the cells 
of the Alga. If the plants were not fatally injured, accommo- 
dation to the new medium took place, followed, after a time, 
by the return of normal growth. 
Richter 4 extended the study to fresh-water Algae, and 
obtained essentially like results. 
Very similar results were earlier obtained by Eschenhagen 5 
in experiments made with moulds. A sudden transfer from 
one solution to another of sufficiently different sugar-content 
proved fatal, the bursting of the hyphal lips occurring as in 
the Siphoneae observed by Noll. If a less violent action 
took place, the hyphae assumed abnormal forms, but as 
accommodation became complete the usual shape and growth 
1 E. Stahl, Zur Biologie der Myxomyceten, Bot. Zeit., 1884, p. 145. 
2 F. Noll, Beitrag zur Kenntnis der physikalischen Vorgange, &c. Arb. d. bot. 
Inst, in Wurzburg, Bd. Ill (1888), p. 496. 
3 F. Oltmanns, Ueber die Bedeutung der Concentrationsanderung des Meer- 
wassers fur das Leben der Algen. Sitzb. d. Konigl. preuss. Akad. d. Wissensch. 
zu Berlin, 1891, p. 193. 
4 A. Richter, Ueber die Anpassung der Siisswasseralgen an Kochsalzlosungen, 
Flora, 1892, p. 4. 
5 F. Eschenhagen, Ueber den Einfluss von Losungen verschiedener Concentration 
auf das Wachsthum von Schimmelpilzen. Dissertation, Stolp, 1889. 
