20 Mr. J. Miers on the Menispermacese. 



in the form of the petals (though constant and very peculiar in 

 each group) is of little importance in a generic point of view : 

 heedless, too, of the carpological features which distinguish 

 these genera, they fused together, after their peculiar method, 

 all the genera of my PlatijgonecB, reducing them to a few spe- 

 cies of Cocculus, corresponding in number with my genera. It 

 is much to be regretted that the authors of the new 'Genera 

 Plantarum^ should have adopted these extreme views in that 

 useful work, and have been thus led to form many erroneous 

 conclusions concerning Menispermacece. It is scarcely possible 

 that this hasty disavowal of valid genera and species can meet 

 with general assent or can be maintained when the different 

 points of structure are carefully compared. If the method of 

 ignoring marked differential features in the floral as well as in 

 the carpological structure be adopted in one tribe, as attempted 

 here, it ought equally to be applied to the other tribes of the 

 family : in such case its many genera, deprived of their precise 

 limits, would collapse, and the whole distribution would again 

 become involved in endless confusion. In order to avoid this, 

 and to preserve one uniform consistency, it appears to me desir- 

 able to maintain Cocculus as a distinct genus of the Platygonea, 

 within the limits I have ascribed to it ; otherwise the genus 

 Cocculus must disappear, as the Nephroica of Loureiro would 

 take its place by right of a priority of many years, or perhaps 

 JSpibaterium of Forster, which is of still older date. 



In regard to the plea before mentioned, that the form of the 

 corolla, even where it assumes uniformly a very peculiar shape, 

 is a character too trivial to be entertained, I might cite hundreds 

 of instances where that feature forms a leading mark of generic 

 distinction j indeed it has been employed successfully in several 

 families by the above-mentioned botanists ; and there can be no 

 especial reason for discarding it in the Menispermacece, particu- 

 larly in the instances oi Nephroica and. Holopeira as distinguished 

 from Cocculus. The carpological structure of Diploclisia is un- 

 questionably distinct from that of the last-mentioned genus ; its 

 putamen and condyle are constructed upon quite a different 

 plan, and its cotyledons and radicle offer very different propor- 

 tions ; while the mode of its inflorescence and the general aspect 

 of the plants afford the most striking marks of distinction. 



The difference in the form of the corolla is so manifest in all 

 these four genera, that, in examining the male plants, it is im- 

 possible to mistake one genus for another; but this is not the 

 case as regards Pachijgone, which has a floral structure hardly 

 different from Cocculus : in both cases the form of the petals 

 and the trimerous arrangement of parts are alike, the only dif- 

 ference being that in the former the outer series of bracteiform 



