16 The Nature and Origin of Stipules. 



rum and some Euphorbiaceae and Balsaminaceae as well as the 

 axillary hairs in some Portulacacese are stipules. 



Clos, D. — Independance, developpement, anomalies des stipules ; Bour- 

 geons a ecailles stipulates. Bull. Soc. Bot. Fr. 26 : 189-193. 1879. 



Stipules have been regarded as appendages of the leaf by Du 

 Petit-Thouars (Cours 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 Rosaceae, Leg- 

 uminosae, Malvaceae, Geraniaceae, etc., the stipules persist alone, 

 the leaves having completely disappeared, whether in the inflor- 

 esence or at the base of stems and branches. 



Under the head of the development of stipules the conflicting 

 opinions of Mercklin and Trecul as to their time of appearance in 

 relation to that of the leaf-blade is referred to. Agreement with 

 Trecul 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. 



In consideration of stipular bud-scales reference is made to 

 their recognition by Linnaeus (Phil. Bot. Ed. 3, 52. 1190), Adan- 

 son (Families des PI. 246, 1163), De Candolle (Ann. Sci. Nat. 

 (Ill), 5 : 321, 1846)* and Lindley (Veg. Kingdom, 283, 1846). 



Golbel, K.. — Beitrage zur Morphologie und Physiologie des Blattes. Pt. I. 

 Die Niederblatter. Bot. Zeit. 38: 753, etc.— 845. 1880. 



This extended treatise deals with bud-scales and the scales of 

 subterranean parts of plants and their homologies with leaves. 

 Speaking of the primordial leaf Gobel says, " it is divided into 

 two parts, a stationary zone which takes no farther part in the 

 leaf-formation and a part out of which the lamina is developed." 

 He calls these parts respectively the leaf-base and upper-leaf and 

 states that the petiole arises after the formation of the blade and 

 is inserted between the two parts. 



Bud-scales are regarded as modified foliage-leaves and divided 

 into those formed from the blade (Syringa), those formed by the 

 leaf-base (jffisculus, Prunus), and those consisting of stipules 

 (Liriodendron, Quercus). In Prunus, etc., the formation of the 

 bud-scales by the union of petiole and stipules is denied on the 

 ground that the continuous separate development of the petiole 

 and stipules can be followed. 



* See also Org. Veg. 2: 213. 1827. 



