28 TERRESPRIAL ADAPTATIONS.

much t0 change, the processes of vegetable life would be interrupted, deranged, distempered. What,’ for instance, would become of our calen- dar of Flora, if the year were lengthened or shortened by six months? Some of the dates would never arrive in the one case, and the ve- getable processes which mark them would be superseded; some seasons would be without dates in the other case, and these periods would be employed in a way hurtful to the plants, and no doubt speedily destructive. We should have not only a year of confusion, but, if it were re- peated and continued, a year of death.

But in the existing state of things, the duration of the earths revolution round the sun, and the duration of the revolution of the vegetable func- tions of most plants are equal. These t\vo pe- riods are adjusted to each other. The stimulants which the elements apply come at such intervals and continue for such times, that the plant is supported in health and vigour, and enabled to reproduce its kind. Just such a portion of time is measured out for the vegetable powers to exe- cute their task, as enables them to do so in the best manner.

Now such an adjustment must surely be ac- cepted as a proof of design, exercised in the for- mation of the world. Why should the solar year be so long and no longer? or, this being of such a length, why should the vegetable cycle be ex-