It is important to distinguish in plants the difference between what may be termed the vegetative and reproductive stages in plants. It is within the every-day experience of the cultivator that so long as a tree is growing vigorously, it will not fruit. If a branch on such an unfruitful tree is "ringed" or in some other way injured, that branch is at once brought to the fruit bearing or reproductive condition. So far we see that there is an antagonism between the vegetative and the reproductive states. Now when the reproductive stage has been reached, we see again a subdivision. The part to which nutrition most freely flows produces most freely female flowers. The part to which nutrition flows less freely yields chiefly male flowers. Any one can see this who examines a larch, a spruce, or a pine.

So, when we speak of vigor promoting fruitful-ness, we must be careful to remember about which condition we are speaking. Vigor is opposed to fruitfulness if by fruitfulness we mean the whole reproductive stage. Vigor favors fruitfulness when we are talking about a plant that has already reached the reproductive stage.