Experimental researches on vegetable assimilation and respiration. XIII. —The development of photosynthetic activity during germination

We must assume that the development of every leaf begins with a stage in which it is incapable of performing the function of assimilation. It is a matter for investigation to determine whether this stage is passed when the tiny leaf first becomes visible in the bud or whether it persists even after the leaf is unfolded and fully green. For seedlings this matter is very important biologically, because it determines when the plant can begin to make additions to its dry weight and start its natural development. Analysis of results of growth experiments on such plants as maize indicates that the early assimilatory power is very feeble.