( 499 J 
this way. Accordingly the best results in the enzyme experiments 
are obtained by crude enzyme finely powdered. 
3. On the Distribution of Indican and the Indigo- 
enzymes in the Plants. 
By the examination of the different parts of indigo- and other 
plants in the two ways described, the distribution of the indican and 
the indigo-enzymes was established. It was thus made evident that 
both commonly occur or lack together. 
They are accumulated in the leafy organs, especially in the 
green leaves; in flowers and flower-buds they are in smaller 
quantity. In the seeds and germs they fail entirely. The roots and 
stems of Polygonum tinctorium and of Indigofera leptostachya are 
also quite or nearly quite devoid of indican and indigo-enzyme. Only 
in transverse sections of branches of the latter, kept for some 
days in strongly diluted indican solution, I could detect traces of 
indigo-blue particularly in the medulla and the medullary rays and 
in the bark, which shows that these parts contain some, but very 
little indigo-enzyme. The absence of enzyme and indican in the stem 
and roots of Polygonum tinctorium can be easily shown as the stems 
of this plant have a great disposition to form radiculae which are, 
as the stems, by their herbaceous nature and broad-celled structure, 
quite fit for such experiments. If the roots are allowed to die off 
in a chloroform-atmosphere they remain colourless; this is likewise 
the case when the dying is occasioned by immersion in mercury 
followed by treatment with ammoniac vapour. But from this follows 
only that indican and enzyme do not occur together; if but either 
of them is present it is not detected by this experiment'), but may 
be demonstrated as follows. 
If indigo-enzyme is added to a decoction made from the stems 
or roots of Polygonum tinctorium, or if this decoction is boiled with 
hydrochloric acid and a little ferrichlorid to decompose the indican and 
oxidise the indoxyl, then no indigo appears; so, indican is absent. 
That in the said parts indigo-enzyme, too, is wanting follows from 
the fact that parts of stems and roots finely crushed in alcohol, after 
filtering off and drying, produce a powder quite inactive on indican- 
solution. Even the growing point and the region of growth of the 
') This should be kept in view with regard to the ‘“alcohol-experiment” of 
Mr, Mozrscr, 
