( 689 ) 
the same time a means of rapidly restoring lost turgor. Schell *) 
considers that tannin in seeds is probably a protection against harmful 
influences from without. Busgkn 2 ) also supposes that tannin affords 
protection to the plant. 
Other authors again have attributed different functions to tannins.. 
According to Gerber *) they prevent the transformation and fermen¬ 
tation of sugar in fruits and Pfeffer *) thinks it very likely, that 
their role also consists in fixing sugars and other substances in the 
cell. Kutscher 4 5 * ) considers it most plausible that tannin serves as a 
respiratory agent and is oxidized in respiration. 
Various other functions have further been attributed to tannins in 
connexion with the metabolism of the plant. Thus Wigand*) supposed 
that the red colouring matters are formed from tannins, a view 
shared by Pick 7 ), Miklkk 8 9 10 ), and Tschirch e ) amongst others. 
Some authors connect tannins with the formation of resin. Wiesner 1 *} 
thinks that starch and cell-wall may be transformed to tannin, and 
subsequently to resin. Schell 11 12 * * ) and Mielke ia ) also regard tannin as 
an intermediate stage between starch and resin and between cellulose 
and resin. Both authors, however, also suppose, that tannin can be 
converted into starch. Bastin and Trimble 1S ) in their investigation 
of the resin-passages of conifers, have also received the impression, 
that tannin is connected with resin formation. 
4) W. Pfeffer, Uber Aufnabme von Anilinfarben in lebende Zellen, Unter- 
suehungen aus dem botan. Institut zu Tubingen, 2. Bd., 1886—1888, p. 810. 
6 ) 1. c. p. 73. 
«) 1. c. 
7) H. Pick, Ueber die Bedeutung des rothen Farbstoffes bei den Phanerogamen 
und die Beziehungen desselben zur Slarkewanderung, Botan. Centralblatt, Jahrg. IV, 
1883, p. 284. ‘ 
.8) g. Mielke, Ueber die Stellung der Gerbsauren itn Stoffwechsel der Pflanzen, 
Programm der Realscbule vpr dem Holstenthore in Hamburg, 1893. Ref. Botan. 
Centralblatt, Jahrg. XV, 1894, Bd. 59, p. 281. 
9) A. Tschirch. Schweiz. Wochenschr. f. Pharm. N 1 .7. Pharm. Gentralbl. N°. 10, 
1891, p. 141. 
10) j Wiesser, Uber die Entstehung des Harzes im lnneren der Pflanzenzellen, 
Sitzungsber. d. Wiener Akad., 1865, 52. Bd. U. Abt. p. 126 and 129. Ref. Jahres- 
ber. uber die Fortschritte der Chemie etc., 1865, p. 627, 
u > 1. c. 
12) 1. c . 
is) E. Bastin and H. Trimble, A contribution to the knowledge of some North 
Amerikan Goniferae, Amer. Journ. Pharm. 68, 1896. 
