19 
precipitates. [In the paper referred to above [ drew atten- 
tion to the fact that they were earlier described errone- 
ously by Loew and Bokorny as protein precipitates. 
To this these authors !) soon replied. 
In connection with the various views on the chemical 
nature of intravital precipitates, [| have further considered 
whether protein might occur in them and subsequently 
performed some experiments on Spirogyra maxima (Hass.) 
Wittr. which in my opinion render much more certain 
the view that the precipitates contain no protein, than 
was already the case. It follows moreover from these 
experiments that the precipitates occur in the cell-sap and 
not in the cytoplasm. I will first explain this point. 
Bokorny*) assumes that in Spirogyra proteosomes are 
formed in the cytoplasm as well as in the cell-sap. He 
thinks he has furnished proof of this by combining the 
formation of proteosomes with abnormal plasmolysis. 
He placed Spirogyra in a mixture of equal parts of a 
10 °/, solution of potassium nitrate and a 0.1 °/, solution of 
caffeine. After the action proteosomes were observed in 
the cytoplasm as well as in the contracted vacuole. 
Kiemm *) agrees with Bokorny with respect to the locali- 
sation of the precipitate in Spirogyra. Klemnm first allowed 
the precipitate to occur and then plasmolysed. 
When Bokorny ‘) first brought about abnormal plasmo- 
lysis with a 10°/, solution of potassium nitrate and sub- 
sequently allowed basic substances to act, he found only 
1) ©. Loew and Th. Bokorny, Aktives Eiweiss und Tannin in 
Pflanzenzellen. l.c. 
?) Th. Bokorny, Neue Untersuchungen über den Vorgang der 
Silberabscheidung durch actives Albumin. 1. c. p. 206 
) P. Klemm, Beitrag zur Erforschung der Aggregationsvorgänge 
in lebenden Pflanzenzellen. 1. c. p. 407. 
4) Th. Bokorny, Ueber die Einwirkung basischer Stoffe auf das 
lebende Protoplasma. 1. c. p. 209. 
2* 
