8 The Nature and Origin of Stipules. 



From these relations, as regards the leaf, interior and exterior 

 stipules are distinguished. 



9. " Interior stipules protect the formation of the following 

 node and leaves. The leaf at the same node develops somewhat 

 earlier or at about the same time. 



10. " Exterior stipules develop before the leaf at the same node 

 and therefore protect their own node with its leaf. 



11. " As stipules are limited in the time during which they are 

 functional, they lose their significance as soon as this purpose is 

 fulfilled. They do not produce buds in their axils except in cases 

 where true leaves are not developed." 



The following statement (p. 227) should be noted. " In some 

 species of Thalictrum the membrane rising above the inner 

 margin of the base of the petiole is the analogue of the ligule." 



Kirschleger, F.— Flora, 28 : 615. 1845. 



The tendril of Cucurbitacese is regarded as a normal stipular 

 formation. 



IMercklin, C. E.— Entwicklungsgeschicte der Blattgestalten. 1846. 

 (Translated into the French in Ann. Sci. Nat. (Ill), 6 : 215-246. 1846.) 



The statements of Mercklin are contrary to those of Regel. 

 He says, '•' In all cases the stipules of the developing leaf appear 

 as portions of the lamina ; it is only later, during the development 

 and elongation of the petiole, that they become sufficiently sepa- 

 rated to be considered as distinct organs. In all simple leaves 

 the stipules never appear at the same time with the first rudiments 

 of the lamina ; they develop only with the inferior parts of the 

 lamina including the petiole." 



" From my observations of stipules I conclude that in common 

 with the leaflets they owe their origin to the common petiole 

 and are formed later than the leaflets." 



lira use, ii- — Einige Benierke iiber den Blumenbau der Fumariacese und 

 Cruciferse. B. Crucifene. Bot. Zeit. 4 : 137-150. 1846. 



Stipules in the Cruciferse are considered (pp. 142-145) and the 

 homology with stipules of the so-called glands at the base of the 

 leaves is established by a careful series of observations upon their 

 development. The glands of the bracts and floral organs are also 

 included.* 



* See also Duchartre, Eev. Bot. 2 : 208. 1845-7 and Norman, Quelquea 

 Observ. de Morph. Veg. 1857. 



