226 Mr. Charles C. Babington on Ranunculus aquatilis. 



brous or hispid carpels ; points in which each of the plants 

 described below is found to vary, except that tripartite leaves 

 have never been noticed in R. circinatus. 



The idea that the different forms concerning which we are 

 treating are caused by the plants being placed in stagnant or 

 swiftly flowing water, or upon nearly dry land, was first, I be- 

 lieve, started by Mr. Woodward in Withering' s arrangement, 

 and adopted by Smith, DeCandolle, and others ; but I have 

 constantly observed R. aquatilis and circinatus inhabiting, side 

 by side, the same stagnant muddy water, or the same pure 

 and swiftly flowing brook, and yet remaining totally unaltered 

 and remarkably different ; I have also gathered R.fluitans in 

 perfectly stagnant ditches, quite preserving its specific distinc- 

 tion, and am convinced that the form and mode of division of 

 the leaves will be found to constitute plain and constant spe- 

 cific characters. I am confirmed in this view by Wallroth, 

 who appears to have studied these plants with peculiar care, 

 and by Gaudin, Mertens, Koch, Schlechtendal, Sturm, and 

 others, who have kept the plants separate, and recorded ob- 

 servations similar to my own. 



In R. aquatilis the submersed leaves (and sometimes, when 

 growing upon mud, all the foliage) are divided into numerous 

 capillary segments, which spread in all directions, so as to form 

 a more or less spherical mass ; in R. circinatus they are divided 

 into capillary segments, but spread only in one plane, so as to 

 present a thin flat surface with a well-defined circular outline, 

 as if an additional quantity of parenchyma only was wanting to 

 form them into an entire circular leaf^ and they have not the 

 slightest tendency to a spherical arrangement ; they are also 

 invariably sessile, that is, have only the amplexicaule sheath 

 between their limb and the stem, whilst in R. aquatilis they have 

 usually a distinct petiole interposed which is often much elon- 

 gated. In R.fluitans the leaves are upon long petioles, and very 

 much elongated^ and repeatedly dichotomous, with a long in- 

 terval between the forks, the divisions taking a parallel direc- 

 tion and not spreading into a spherical mass, nor yet remaining 

 in one plane surface. 



The persistent style also and the shape of the carpels ought 

 to be attended to ; in R. aquatilis the carpel is usually ovate, 



