THE CHLOROPHYLL APPARATUS 159 
A process which at first appeared to involve a 
mechanism resembling that of the chlorophyll apparatus 
was discovered some years ago by Engelmann. Certain 
bacteria which contain a purple pigment were found to 
possess the power of photosynthesis. The pigment was 
thought to be allied to chlorophyll and to possess the same 
power of absorbing and utilising the radiant energy of 
light. Recent researches make it probable that, like the 
red seaweeds, these organisms contain a certain amount of 
chlorophyll, together with the purple pigment. 
Saprophytic and parasitic fungi, which contain no 
chlorophyll, have no power of photosynthesis. They are 
compelled to absorb their carbohydrates from the medium 
in which they grow, and they take them in chiefly in the 
form of sugar. Parasitic phanerogams depend upon a 
similar source of supply. 
