THEIR NOMENCLATURE. 131 
subordinate varieties. They still appeared the same in the ‘ Flora 
Britannica,’ as also in the ‘English Flora’ just a century later 
than the third edition of Ray’s ‘ Synopsis’ above quoted. 
In the ‘Flora Oxoniensis,’ before the dates of Smith’s Floras, 
Sibthorpe had treated the same plants as four separate species, 
under the names of heterophyllus, aquatilis, circinatus, and 
Jlwiatilis. Three of these names were adopted from Wiggers 
(or Weber) ; that of circinatus being a specific adaptation of the 
adjective used in the old name-description before quoted from 
Ray. In Gray’s ‘ Natural Arrangement of British Plants,’ dated 
in 1821, all four were also continued as separate species; the 
heterophyllus being subdivided into two species distinguished by 
their “ smooth” or “ bristly” achenes ; a variety peltatus also being 
distinguished by its leaves “ orbicular, three-lobed, peltate.” This 
was a movement towards the more recent pseudo-specific sub- 
divisions of heterophyllus. 
In the ‘British Flora’ of Hooker, in which a leading aim 
was condensation of matter, occasionally becoming injudicious 
omissions, Smith’s single species was adhered to; the fourth 
variety fluviatilis or fluitans being entirely ignored in some 
editions, but it was restored in the fifth. (All the editions are not 
at hand, only three, five, six, eight.) In edition sixth, 1850, 
Dr. Arnott re-promoted fluitans and circinatus to the “rank of 
species”; keeping the specific name aquatilis to include hetero- 
phyllus and pantothrix, as the two forms or varieties of that 
species. The same’ arrangement is continued in edition eighth, 
1860, with some mention of the segregate species of the ‘ Manual,’ 
treated as subordinate forms under the two primary varieties 
mentioned above. 
We can now turn to the ‘Manual of British Botany,’ a little 
book, but as great an Innovator among the various Floras of 
Britain, as Gray’s great book the ‘Natural Arrangement’ had 
been. The latter work, being in some respects a quarter of a 
century in advance of its cotemporaries in 1821, was neglected 
accordingly ; thus it effected neither good nor harm. The inno- 
vations of the ‘ Manual’ have come much into use. Occasionally 
