The word _petal_ was preserved by Tournefort, handed down by Linnæus and the two De Jussieus, and afterwards adopted by all botanists with the signification given to it by the ancients. Now, as the calyx may also consist of leaflets, which are generally green, Necker conceived the idea of applying to them the same term, after substituting an _s_ for the initial letter _p_. Thus was created the word _sepal_. The innovation, I must point out, was not unanimously adopted. Many botanists continued to use the words "calicinal leaflets," introduced by Linnæus; others, though they adopted the innovation, protested against it. But leaving the _word_, let us return to the _thing_. The calyx consists originally of several leaflets. Is the monophyllous or monosepalous calyx a transformation due to the junction of the primitive leaflets? Observation replies in the affirmative. In the formation of junctures or adhesions nature proceeds from beneath to above. Our language proceeds inversely to nature: we speak of a lobed, dentated, or partite calyx, as if it were primarily monophyllous, and its more or less profound divisions (indicated by the words "lobed," "dentated," "partite") were but consecutive results, produced from above to below. The truth is, that the calicinal divisions, which we call _lobes_, _lacinias_, and the like, are but the tops of leaflets united at their base. The monophyllous calyx (formed of one piece) is, therefore, simply the result of a more or less complete union of the leaflets composing, properly speaking, the calicinal whorl. This whorl is originally _polyphyllous_; that is to say, formed of several distinct parts. If it were, in the first place, _monophyllous_, it would be impossible to understand how its divisions are made from top to bottom, since nature, in its developments, proceeds from bottom to top. In the final analysis, then, it is an error to consider the calyx as a cup, primarily formed of a single piece. * * * * * Grew, an English botanist of the eighteenth century, seems to have been the first who made use of the word _calyx_. "I call a calyx," he says,[60] "the external portion of the flower, which enfolds the others, whether it be all in one piece, as in the violets, or divided, as in the roses." * * * * *