[en] Zeller wrote that "Willstätter has shown that, as astonishing as it may be, the chlorophyll content of the plants varies only within very small limits and that the ratio of the two components a and b is almost always the same, i.e. 3:1." He summarises in this sentence the general belief which developed after the publication of the remarkable book of Willstätter and Stoll. This belief was to consider chlorophyll accumulation in the growing leaf as simply resulting from the continuous synthesis of new molecules adding to the former ones. One can easily prove that the process is in fact more complex.
