525 
microscope I saw that the brightly coloured orange-yellow plastids 
quickly formed orange-yellow globules; crystals soon appeared in 
these globules. While the globules dissolve the crystals remain behind. 
These are orange-red plates and aggregates which very slowly dissolve 
in the phenol mixtures. To investigate these, the preparations can be 
washed out successively with dilute alcohol (70 °/,) and with water. 
With reagents they give the reactions characteristic of carotinoids. 
When parts of the flower of Asclepias curassavica are placed in 
the mixture of phenol and glycerine, there quickly appear in all 
the cells numerous light and dark red or orange-red (Kl. et V. 11, 
46, 51, 71, 91) crystals, in the same way as in Erysimum Perofs- 
kianum, among which were many plates and aggregates. They do 
not dissolve in the phenol solution; at any rate after three days they 
were still unchanged. When investigated with reagents in the way 
indicated above, they show the reactions proper to carotinoids. In Urtica 
dioica orange-red (81) erystal aggregates are formed here and there 
in the tissue, which after three days are still present in the mixture of 
phenol and glycerine. In the ligulate florets of Taraxacum officinale 
yellow globules soon arise; in this case no crystals occur; the globules 
completely dissolve. Clearly in these four objects carotinoids occur, 
which differ greatly with respect to their solubility in a mixture of 
phenol and glycerine (8 to 1). and are either insoluble or dissolve 
slowly or readily. In the last case the carotinoids do not separate. 
Wirrsrärrer and Mime *) have dealt with the question whether, 
in addition to carotin, xanthophyll is also present as such in the 
living plant and have answered it affirmatively. Both substances, 
can indeed be separated with simple solvents, carotin from dried 
leaves with petroleum ether, xanthophyll from alcoholic extracts of 
fresh leaves according to the “Entmischungsmethoden” of G. STOKzs, 
U. Kraus, H. C. SorBy and R. Sacnssr ®). It is therefore reasonable 
to assume that in some cases the use of simple solvents in which 
the carotinoids themselves are but little or not soluble, might lead 
to the crystallisation of these substances. In a few cases | have 
indeed succeeded in doing this. 
With the ligulate florets of Taraxacum officinale and Doronicum 
Pardalianches I did at first not succeed in erystallising even a 
part of the carotinoid by means of the potash method. It remained 
in solution in the yellow or orange-vellow globules which had formed 
in the cells. When 1 had treated the ligulate florets for a very 
short time with absolute alcohol or a certain quantity with very 
lep. 10. 
2) See WILLSTATTER und ISLER, l.c. p. 275 et seq. 
