696 
colouring matters, which must be considered to be carotinoids. Zoer 
found a yellow carotinoid such as is commonly found in green 
plants and a red one to which the alga is indebted for its frequently 
dark blood- or brown-red colour and for its name. Zoer succeeded 
in separating the two colouring matters in the following way. The 
erude alcoholic extract of the alga was saponified with caustic soda. 
The chlorophyll was thus changed into a sodium compound, the fat 
into a soap and glycerine, the yellow carotinoid was set free and 
the-red one converted into a sodium compound insoluble in water. 
When the saponification products after dilution with water, were 
treated with petroleum ether, the yellow carotinoid was removed, 
whilst the sodium compound of the red one separated out. After 
purifying the sodium compound the carotinoid was set free by means 
of dilute sulphuric acid, it was taken up in ether and investigated 
spectroscopically. The red carotinoid differs spectroscopically from 
the yellow, in colour and in the colour of its solutions, and also in 
its power of combining with alkalis and alkaline earths. 
Haematococcus pluvialis has recently also been investigated by 
JacogseN *). By means of Moriscn’s potash method he obtained sepa- 
ration of erystals, but on the other hand he was unsuccessful with 
dilute acids and with Tswerrt’s resorcinol solution. The accuracy of 
Zorr’s results remained undecided. 
Mr. JAcoBsEN was kind enough to send me a culture of Haemato- 
coecus pluvialis on agar, and thus I was given an opportunity of 
studying this remarkable alga and of confirming the above mentioned 
conclusions of JACOBSEN. As is clearly shown by his beautiful plates, 
the aplanospores differ very much as regards colour; some have 
a green content, in consequence of the chlorophyll they contain, 
others are green at the periphery and red in the centre, whilst in 
others again the green of the chlorophyll is entirely masked and 
there seems to be only a red content. The red colouring matter is 
combined with a liquid fatty substance or, more accurately, is 
dissolved in it. This substance occurs in the form of globules in the 
cell-content. | 
As is to be expected, aplanospores which at first sight show 
differences, yield different results on investigation. In the green spores 
orange-yellow crystals were quickly separated out by Moriscu’s rea- 
gent; generally these are shaped like curved needles, which are 
often united into bundles; sometimes orange-yellow crystal plates 
were also observed. In addition to these plates, there were also a 
1) H. G. Jacosson. Die Kulturbedingungen von Haematococcus pluvialis, Folia 
Microbiologica, I, 1912, p. 24 et seq. . 
