Of these, however, there are many species, all of which agree in some important characteristic or characteristics of the genus by which it is distinguished from other genera.

All so agreeing may be called Plantae Ranunculaceae ; but what common property connects lark- spur, columbine, or monk's-hood with Ranunculus ? None distinguishable before the formation of the seed-vessel.

Then, indeed, it appears that these plants agree in this ; viz.

That their ovaria are either in more than one row ; or, if soli- tary, then the stamens are opposite to the petals.

These characters connect together in classification plants widely dissimilar in trunk, and leaf, and blossom, and exterior form of seed-vessel, and in general habits of growth.