deciding whether there were any real difference of structure between these accessory parts or not, and it might puzzle an adept to determine the question. For instance, whether the nectary in Salix, different in the barren and fertile flowers of some species, should lead us to keep that genus in Dioecia, though in other species the nectary is precisely alike in both the kinds, and occasionally an abortive germen occurs in the barren flowers, as stamens do, more rarely, in some fertile ones. Considering all this, I should refer Salix to Diandria Monogynia.
With respect to those Monoecious or Dioecious genera whose barren flowers are decidedly unlike the fertile ones, the former being in a catkin, the latter not, as Corylus, Quercus, &c., I conceive nothing more pernicious or troublesome can be attempted than to remove them to the Classes of united flowers. They meet with no allies there, but, on the contrary, form so natural an assemblage by themselves, as to be unanimously kept separate by the authors of every natural system that has ap-
