Under this title a summary of the opinions of botanical au thorities as to the true nature of stipules is given and the different theories are briefly discussed.
Various leaves have been considered as stipules, for example the primary leaves of Asparagus (Dutrochet), the first leaves of the branches of Verbena aphylla Gill Hook. (Hooker, Dot.
Misc. 1: 116. 1830) and of the Piperacere ( C. DeCandolle, Wm. sur les Piper. 18-19, 1866), and the first two leaves of the axillary buds of many Solanacem.
The appendages sometimes accompanying the leaf in some Con. volvulacepe, as Ipomea stipulacea Sweet., have been considered as stipules (Jacquin. Pl. Hort. Schoenbr. Descr. et lc. 2: 39. 1797).
Many have regarded stipules as leaflets, as for example in Vibernum (Baillon, Adans. 1: 372. 1860), and the lower leaflets in many plants have been taken for stipules, as in Cobcea scan dens Cay. (Blume. Rumphia 3: 142. 1837), and Lotus tetraphyllus .purr. (Linnicus, Trinius, E. Meyer, Fischer.) In 1844 Wydler declared that stipules belong to the sheath and cites examples of transition between the two kinds of organs in the Rosacere, Polygonacex, Leguminosre, etc. Stipules, in con nection with the sheath have been ascribed to Ranunculus, Iso pyrum and Thalietrum by Lloyd (Fl. de POnest de Fr. Ed. 2, 1868), to Caltha by Wydler, Kiitzing (Grundz. der phil. Dot. 684, 1851-52) and Hooker. They have been recognized in the scales of the stems of the Aroids.
The so-called " decurrences " of leaves do not differ anatomically from stipules and are to be considered as identical with them, as for example in Crotalaria.
The tendril of the Cucurbitaceic has been regarded as a stipule by Seringe (M6m. Soc. Hist. Nat. Geniiv. 3 : 1-31. 1825), De Can dolle (Organ. Veg. 1 : 336. 1827), Kirschleger (Flora, 28 : 615. 1845), Stoks (Ann. Nat. Hist. 1846), Payer (E16m. de Bot. 53. 1857-58), Parlatore, etc. Those of Smilax have been so consid ered by Cauvet (Bull. Soc. Bot. Fr. 12: 241. 1865), but are looked
on by Clos as " simple prolongations of the flbro-vascular bundles of the petiole without morphological signification." The spines of the orange are considered as stipules by Du Thonars (Conn de Phytol. 47. 1820). Clos regards them as branches and those of Anzaranthus spinosus L. as leaves, though they are considered stipular by Lamarck (Encyc. Nleth. 2 : 118. 1786). Vibes shows stipular spines in some species. The spines of Xanthium spinosum L. mentioned by Sachs as occupying the place of stipules, Clos regards as representing pistillate flowers. He looks with disfavor on the doctrine that the glands at the base of the leaves hi Resedacere, Crucifer:e, Epilobium, Lyth ruin and some Euphorbiacem and Balsaminacere as well as the axillary hairs in some Portulacacere are stipules.
Cios, D.—Ind6pendance, dereloppement, anomalies des stipules ; Bour geons a &allies stipulaires. Bull. Soc. Bot. Fr. 26 : 189-193. 1879.
Stipules have been regarded as appendages of the leaf by Du Petit-Thomas (Coors de Phytol. 46, 1820), Aug. St. Hilaire (Lecons de Bot. 189, 1840), G. St. Pierre and F. J. Lestiboudois.
Clos agrees with Agardh in considering stipules as independent organs, giving as his reason that frequently in the Rosacete, Leg uminosie, Malvacete, Geraniaeeie, etc., the stipules persist alone, the leaves having completely disappeared, whether in the inflor esenee or at the base of stems and branches.
Under the head of the development of stipules the conflicting opinions of Mercklin and Tr6cul as to their time of appearance in relation to that of the leaf-blade is referred to. Agreement with Trdcul is indicated and the evidence is not considered sufficient as a basis for the theory of the autonomy of stipules on the ground that they appear before the leaf-blade.