326 HETEROMORPHY. 
Veget., t. i, p. 155, tab. xxxvi, Mentha, &c. Alph. de Candolle, ‘ Neue 
Denkschr. Allg. Schweiz. Gesellschft.,’ band v, tab. vi, Valeriana. Du- 
chartre, ‘Ann. Sc. Nat.,’ ser. 3, vol. i, p. 292. ‘ Gardeners’ Chronicle,’ 
July 5, 1856, p. 452, ¢. ic. wylogy., spiral branches from Guatemala— 
tree not known. 
Spiral twisting of the leaf 1s scarcely of so common oc- 
currence as the corresponding condition in the stem. 
In Alstremeria it occurs normally, as also in some 
erasses. In the variety annularis of Salix babylonica 
the leaf is constantly coiled round spirally. A similar 
contortion occurs in a variety of Codicewm variegatum 
lately introduced from the islands of the South Seas 
by Mr. J. G. Veitch. 
Fern fronds are occasionally found twisted m the 
same manner, e.g. Scolopendriwm vulgare var. spirale. 
Adventitious tendrils—-Under ordinary circumstances 
tendrils may be described as modifications of the leaf, 
the stipule, the branch, or of the flower stalk, so that 
it is not a matter of surprise to find tendrils occasion- 
ally springing from the sepals or petals, as indeed 
happens normally in Hodgsonia, Strophanthus, &e. 
M. Decaisne’ found a flower of the melon in which 
one of the segments of the calyx was prolonged into 
a tendril, and Kirschlegér records a similar instance in 
the cucumber, while Mr. Holland (‘Science Gossip,’ 
_ 1865, p. 105) mentions a case in which one of the 
prickles on the fruit of a cucumber had grown out ito 
a tendril. 
In Cobea scandens the foliar nature of the tendril is 
shown by the occasional presence of a small leaflet on 
one of the branches of the tendril, and a similar 
appearance may frequently be seen in Hecremocarpus 
scaber. On the other hand, in the vine, the axial nature 
of the tendril is revealed by the not infrequent presence 
of flowers or berries on them, as also in Modeeca and 
some Passifloracee. 
1 Moore, ‘ Nature-printed Ferns,’ 8vo edition, vol. u, p. 183. 
2 «Bull. Soc. Bot. Fr.,’ 1860, vol. vii, p. 461. See also Naudin, ‘ Ann. 
Sc. Nat.,’ 4 ser., t. iv, p. 5. Clos, ‘Bull. Soc. Bot. Fr.,’ t, ii, p, 546. 
