454 Ill. SEGREGATES AND 
rhizomes of the two species differ in no wise “nullo modo,” how 
did the Lady named manage to distinguish one from the other by 
a difference in leaf-growth, depending entirely on the difference of 
underground stem or rhizome ? 
It may be useful to explain here, however, that plants of 
spinulosa may be found often enough without rhizomes extending 
horizontally under-ground. For example, such plants may be seen 
growing above the surface of the ground, about the branching 
stocks of alder bushes, in coppices periodically cut down, or on the 
mossy trunks of trees in swamps. Horizontal extension is only 
slightly possible in such situations; but the tendency to it is 
shewn by the crowns of spinulosa loosely dividing into small tufts 
of leaves, after few years of growth; not remaining like the dense 
crowns of dilatata under similar conditions. And there are still 
the other differences, in the form and colour of the scales, to assist 
diagnosis. But this is digressive ; the object properly before us at 
present, is the change of segregate nomenclature, rather than the 
purely distinctive characters. 
In 1858 Mr. Bentham stood not alone among us in England, 
by uniting into one all the three species now more usually 
accepted as distinct. Sir William Hooker was still doing the 
same up to the sixth edition of the ‘British Flora.’ (Edition 
seventh has not come under my own examination.) But in edition 
eighth the late Dr. Arnott diverged rather remarkably from that 
aggregation. Both the other great Botanists named had kept 
cristata quite apart from their inclusive spinulosa ; Hooker even 
interposing Filia mas and rigida between them in his Flora; 
while Bentham, more true to nature, has avoided that unnatural 
separation, by bringing the two former into immediate sequence. 
Dr. Arnott equally makes two aggregate species out of the four ; 
but he does this in a different manner, namely by uniting cristatu 
and spinulosa; thus leaving the Hookerian and Benthamian 
aggregate reduced to dilatata with @mula, under the name of 
Aspidium dilatatum. This is a curious instance of discordant 
views ; for it is taking away a part of one species (fide Hooker and 
Bentham) and patching it on to another and distinct species (fide 
