126 
R. H. Compton. 
opposite to the plumule. In the region of the funicle is present a 
small quantity of extra-embryonal food tissue, whether endosperm 
or perisperm being of course unascertainable : this is completely 
resorbed over the greater part of the embryo. This fact appears 
to be exceptional in an order characteristically devoid of “ endosperm.” 
The embryo (Fig. 12) is a mass of tissue about -36 mm. long, 
shewing distinct polarity. Differentiation is but slight. The whole 
posterior mass of cells is a passive reserve store-house, and only the 
anterior end of the embryo is meristematic. Cotyledons (in the 
ordinary sense of the word) are absent, and two papillae of unequal size 
are the only protuberances. The “plumule” lies between, and may 
be regarded as arising laterally on one papilla, or preferably as pro¬ 
ducing the smaller papilla at a period subsequent to the larger. 
The whole structure is in some degree parallel to that in U.orbiculata? 
The seeds are borne in a globose capsule, on a spongy free 
central placenta. From their small size and hairy appendages, as 
well as from the habitat of the plant, they appear to be adapted for 
dispersal by wind. 
General Considerations. 
The question of the morphological value of the various vege¬ 
tative structures found in the genus Utricularia has given rise to 
much discussion from various points of view. Hovelacque 2 con¬ 
sidered that the runners are “feuilles reduites a leurs nervures.” 
A similar view was taken by Pringsheim 3 and others in such cases 
as U. vulgaris, owing to the definite growth of the apparently lateral 
branching bladder-bearing structures in that species. This view 
has been developed by Goebel, who succinctly states the arguments 
in his “ Organography.” 1 Schenck 5 took the opposed view that the 
runners are caulome structures and are to be compared with the 
stolons of the strawberry. Schimper 6 took a similar view, with the 
addition of the theory that the leaf-like organs of many species of 
Utricularia have arisen by a flattening of caulome structures. 
The simple view, viz., that the “ leaves ” are phyllomes and the 
runners caulomes has also been held, but there now seems to be no 
1 Goebel. Ann. Jard. Buit. IX., p. 59 and PI. X. 
2 Comptes Rendus CV., 1887, p. 692, CVI., p. 310. 
3 Monatsber. d. Konigl. Akad. d. Wiss., Berlin, 1869. 
4 Engl, edition, 1905, II., p. 239. 
3 Pringsh. Jahrb. XXIII., 1886, p. 218. 
6 Bot. Zeit., 1882, p. 241. 
Bot, Centralb. XVII., p. 257. 
