OF MARGINS OF LEAVES, ETC. 25 
Diss.,’ tab., 106) will show how easy the passage is 
from a peltate to a tubular leaf. In these cases the 
tubular form may rather be due to dilatation than to 
cohesion. M. Kickx' mentions an instance of the kind 
in the leaves of a species of Nicotiana, and also figures 
the leaf of a rose in which two opposite leaflets 
presented themselves in the form of stalked cups. 
Schlechtendal* notices something of the same kind in 
the leaf of Amorpha fruticosa; Treviranus® in that of 
Aristolochia Sipho. 
M. Puel* describes a leaf of Polygonatum multiflorum, 
the margins of which were so completely united to- 
gether, as only to leave a circular aperture at the top, 
through which passed the ends of the leaves. The 
Rev. Mr. Hincks, at the meeting of the British As- 
sociation at Newcastle (1838), showed a leaf of a Tulip, 
whose margins were so united that the whole leaf 
served as a hood, and was carried upwards by the 
growing flower like the calyptra of a Moss. 
The margins of the stipules are also occasionally 
united, so as to form a little horn-shaped tube. I have 
met with instances of this kind in the common white 
clover, T'rifoliwm repens, where on each side of the base 
of the petiole the stipules had the form just indicated. 
That the bracts also may assume this condition, may be 
inferred from the peculiar horn-like structures of Mar- 
graavia, Which appear to origimate from the union of 
the margins of the reflected leaf. 
Tubular petals occur normally in some flowers, as 
Helleborus, Hpimediwm, Viola, &c., and as an excep- 
tional occurrence I have seen them in Ranunculus repens, 
while in Hranthis hyemalis transitions may frequently 
be seen between the flat outer segments of the perianth 
and the tubular petals. To Dr. Sankey, of Sandywell 
Park, I am indebted for the flower of a Pelargonium, 
1 «Bull. Acad. Roy. Bruxelles,’ t. xviii, p. i and p. 591. 
2 * Linnea,’ tom. 13, p. 383. 
: ,  Verhandl. Nat. Hist. Vereins,’ 1859, Bonn, tom. xvi, tab. 3. 
* «Bull. Soc. Bot. Fr.,’ vol. i, p. 62. 
