( 690 ) 
According to Buignet l ) tannin in fruits contributes to the formation 
of sugar and according to Stadler *) it supplies in the nectaries of 
Oenothera and Saxifraga the material for the formation of honey. 
In connexion with the physiological significance of tannins in plant 
metabolism, I think it desirable to point out, what results botanists 
have arrived at with regard to the translocation and origin of tannins. 
Some investigators suppose that tannin can be transported in the 
plant, namely Kraus, Moeller, and Westermaier. According to Kraus *) 
tannin travels as such, Moeller 4 ) thinks it probable, that carbo¬ 
hydrates are transported in the form of tannin compounds. Wester- 
maier •) leaves it an open question whether tannin travels as -such, 
and whether starch travels in the form of a soluble carbohydrate or 
in that of tannin. 
The opinions of botanists are divided as to the origin of tannins 
in the plant. As was stated above, tannin is according to Schleiden 8 ) 
a decomposition product of the cell wall. According to Th. Hartog 7 ) 
it arises from starch during the germination of Quercus pedunculata. 
Similarly according to Schell 8 ) tannin is formed from starch in the 
germination of the seeds of Faba vulgaris and Pisum sativum. 
Mielke 9 ) supposes that tannin is formed from carbohydrates, from 
tannin glucosides, and also from starch and from cellulose. Wester- 
maier 10 ) regards it as an assimilation product but supposes that it is 
also formed by the decomposition of proteins. According to Schroeder u ) 
it is formed by oxidation from organic material present in the plant. 
Kraus 1 *) thinks that it is a decomposition product of amido-compound 3 
formed durin g the synthesis of proteins. The observations of Moeller 1S ) 
!\ H ‘ RuiGNET ’ R echerches sur la matiere sucree contenue dans les fruits 
aeKtes son origme sa nature et ses transformations, Compl. rend. 51, p. 894. 
Blulhen, Beriin^886 e,t,aSe Kenntmss der Nectarien und der Biologie der 
.*> KRAUS ’ Grundlinien zu einer Physiologie des Gerbstoffs, 1889, p. 20. 
ssuie. SET deuS T0 ‘ tanm “ 
d J N ™ e BeiW * e 2ur Kenntn® der phjsiologischen Bedeutung 
»-^ss. zzsrrsxssr** * “■* *>•* -• 
*) l.c. p. 141. 
7 ) l.c. p. 102. 
8 ) l.c. 
*) l.c. 
“) IjT B edeUtU “ 8 deS Gerbstoffes “ den Pflanzen, Lc..p. 1124. 
12 ) Grundlinien, p. 47. 
JUlwf^ D1,urw - Vereins f - Nen-Vorpommem und Rflgen in Greifs- 
