Anatomy and Morphology of Utricularia brachiata. 129 
important, there is little reason for relating the papillae to cotyledons: 
in some aquatic species a large number of such papillae are present, 
and in U. brachiata the two papillae arise successively and not 
simultaneously on the embryo. 
Goebel remarks, “ We find all transitions between foliage-leaves 
and stolons,” but the nature of these transitions rather points to 
the reverse view to that which he upholds. The flattened “ foliage- 
leaves ” may branch repeatedly, and the branches may become 
runners or leaves': their veins may be prolonged into runners 
beyond the lamina. 2 Also some leaves are found shewing conditions 
which suggest a progressive flattening rather than reduction 
(Fig. 5, A). 
The further fact that “ leaves and stolons are alike in their 
position on the seedling,” 3 clearly does not support one theory rather 
than the other. 
Numerous other facts point to the view that the leaf-like organs 
are of caulome nature. The runners are of unlimited growth, a 
feature unknown among true leaves. 4 It is true that a possible 
parallel may here be drawn with the fronds of certain Ferns, but it 
must be borne in mind that it is by no means certain that the fern- 
frond is homologous with the angiosperm leaf; and moreover that 
a parallel between groups so far removed in the natural system of 
classification can have little value. Further, the transformed 
leaves of such water-plants as Limnophila heterophylla, and Ranun¬ 
culus aquatilis are structures of limited growth, and very unlike the 
runners of the land species of Utricularia. 
Then again the runners may at certain points produce rosettes 
of leaves and new runners, in a manner strongly suggestive of the 
stolons of such a plant as Ajuga replans, in which the stolon bears 
at a node an erect flowering axis and a number of diageotropic 
lateral shoots. Similar phenomena in leaves are very rare, being 
confined to Ferns (with respect to which the same objections apply), 
Begonia, Bryophyllum and one or two other cases. 
The formation of tubers of various types is frequent in the 
genus Utricularia : they are always developed by a swelling of the 
runners, either terminally or at a point in the course of the runner. 
1 Goebel. Ann. Jard. Buit. IX., 1891, Plate VI., &c. 
2 Ridley. Ann. Bot. II. On a new species of Utricularia, &c., 
p. 305. 
s Goebel. Organograpny, Engl. Ed. II., p. 240. 
4 Such a case as Tumboa has clearly no real significance here as 
a parallel. 
