The Nature and Origin of Stipules. 5 



ted into scales form the covering of the young shoot. This oc- 

 curs in petiolate leaves without stipules, as in the walnut, ash 

 and horse-chestnut. 



''3. Buds are stipular when the scales are formed, not by the 

 leaves, but by the stipules which are not united with the petioles. 

 Of these there are two sorts, — those which are formed by a great 

 number of stipules enclosing a young shoot collectively, as in 

 oaks, willows and elms, and those in which the stipules, free or 

 united b^' their exterior margins, form a peculiar envelope for each 

 leaf, as in Ficus and the magnolias. 



" 4. When the stipules are adherent with the petiole, these two 

 organs united into one form the bud scales, and are named ful- 

 cral. This occurs in most of the Rosacese, and the scales are 

 frequently three-lobed or three-toothed, indicating the origin of 

 the scale formed by the petiole and the two stipules united to- 

 gether." Plate 21, figure 9, shows the progressive change from 

 scales to foliage-leaves in buds that are fulcral in nature. 



Biscltoff, G. W.— Lehrbuch der Botanik. 177-183. 1834. 



The subject is here more fully outlined than in De Candolle's 

 Organographie. Stipules are defined as peculiar leafy expan- 

 sions at the base of a free middle leaf. They are recognized as 

 belonging to the leaf on the ground of their frequent connection 

 with the petiole, the receiving of their vascular bundles from 

 those of the leaf and the absence of buds from their axils. Va- 

 rious kinds of stipules are described and the ochrea,the ligule, the 

 stipule in the Naiadacese and the ochrea of palms are included 

 with stipular formations. 



L.indley, Jolin.— Introduction to Botany, 99. 1832. 



The following statement is of interest : " The exact analogy of 

 stipules is not well made out. I am clearly of opinion that, not- 

 withstanding the difference in their appearance, they are really 

 accessory leaves ; because they are occasionally transformed into 

 leaves, as in Bosa bracteata, because they are often indistinguish- 

 able from leaves of which they obviously perform all the func- 

 tions, as in Lafhyrus, and because there are cases in which buds 

 develop in their axilla, as in Salix, a property peculiar to leaves 

 and their modifications." The character of stipules is denied to 

 the tendril of the Cucurbitacea? and the tendrils of SwuZaa: (p. 96) 

 are regarded as lateral branches of the petiole. 



Annals N. Y. Acad. Sci., X. April, 1897.— 2. 



