A Hypothesis Concerning Vernalization

Let us now try to assemble the facts compiled thus far into a hypothesis concerning the events occurring in vernalization (Fig. 238). Two hypotheses that resemble each other in important points were put forward by Gregory and Purvis and by Melchers and Lang. 

Accordingly, one can call it Vernalin. Now this complies with the fact that during vernalization an end product gradually accumulates over several reaction steps. As far as the chemistry of C is concerned the possibility of its being a gibberellin is discussed. The main reason for saying this is that gibberellins can substitute for the effect of low temperature. 

In our discussion of vernalization we have more than once mentioned the dependence of flower formation on the length of day. A dependence of this kind is shown not only by species requiring vernalization but by very many others too. 

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