16 
on the subject of precipitation in living plant cells by 
various basic substances. In these publications, the same 
points generally have been stated, so that they can here 
be dealt with together. 
In the opinion of these two investigators the precipitates 
which have been caused in the cells by ammonium car- 
bonate, antipyrine and caffeine consist of active protein. 
The bodies of which the precipitates are composed, called 
by these writers proteosomes, can be formed both in the 
protoplasm and in the cell-sap. According to Loew and 
Bokorny the formation of proteosomes is a real vital 
reaction. When the cells have been killed, the reagents 
mentioned cannot any longer bring about the phenomenon, 
because the active protein has been changed into passive 
protein. 
The two authors describe peculiarities of the precipitates 
and mention positive results which they obtained with 
various protein reagents. The precipitates are stated to 
be composed either exclusively of active protein or they 
contain also other substances, such as tannin, but it is 
emphatically declared in this connection, that the admixture 
of other substances is “unwesentlich”. 
p. 369. XL. Bd. p. 161 and 194. — Versuche über aktives Eiweiss 
für Vorlesung und Praktikum. Biologisches Centralblatt. 1891. XI. 
p. 5. — Zur Chemie der Proteosomen. Flora. 1892. Ergänzungsb. 
p. 117. — Aktives Fiweiss und Tannin in Pflanzenzellen. Flora. Cl. 1911. 
p. 113—116. Autoreferat. Botan. Centralblatt. 32. Jahrg. 1911. I. Halbjahr. 
Bd’ 116: 1911-"p. 361. 
Th. Bokorny, Neue Untersuchungen über den Vorgang der Silber- 
abscheidung durch actives Albumin. Jahrb. f. wiss. Bot. XVIII. Bd. 1887. 
p. 194 — Ueber die Einwirkung basischer Stoffe auf das lebende 
Protoplasma. 1. c. Bd. XIX. 1888. p. 206—220. — Ueber Aggregation, 
L c. Bd. XX. 1889. p. 427. — Zur Kenntniss des Cytoplasmas. Ber. 
d. d. bot. Gesellsch. Bd. VIII 1890. p. 101. — Zur Proteosomen- 
bildung in den Blättern der Crassulaceen. 1. c. Bd. X. 1892. p. 619. — 
Ueber das Vorkommen des Gerbstoffes im Pflanzenreiche und seine 
Beziehung zum activen Albumin. Chemiker-Zeit. 1896. No. 103. p. 1022 
