170 ALTliKATlON 01' J'OSITION. 



In the genus Alliuin an analogous formation of little 

 buds or bulbils takes place in lieu of flowers ; this is 

 specially the case with A. vineale, the flowers of which 

 are rarely seen. 



Other illustrations of a similar character, where the 

 adventitious leaf-buds are mixed in amongst the flower- 

 buds, are cited under the head of Prolification of the 

 Inflorescence. 



Formation of buds on leaves. The formation of little 

 bulbs upon the surfaces or edges of leaves, forming 

 what are called viviparous leaves, has long been familiar 

 to botanists amongst Alliums. Professor Alexander 

 Braun,^ who has paid much attention to this subject, 

 divides cases of this kind according to the position of 

 the buds ; thus, for instance, they are sometimes formed 

 upon the upper portion of the leaf or petiole, as in 

 many ferns,. in Nymjjhcea guineensis, some Arads, &c. 

 The same condition has been met with as a teratological 

 occurrence in the leaves of Gardmwme pratensis, Hya- 

 cinthus Pmizohii, Drosera intermedial^ Arabis pumila^ 

 Ghelidoniunn majus, Chirita sin&iisis,^ JEpiscia hicolor,^ 

 Zamia^ &c. Many species of Begania possess the power 

 of emitting buds from the petioles and veins of the 

 leaf; the little ramenta or scales which so plentifiiUy 

 beset the surface of some of these plants likewise, in 

 some instances, pass gradually into leaves. B. phyllo- 

 manlaeaf Mart., is the species best known as manifest- 

 ing this tendency, but others have it also.^ 



Buds are also very often formed upon the margins 

 of the leaf, the best known instance of which occurs in 



' ' Ann. Scienc. Nat.,' vol. xiv, i860, p. 13. 



Naudin, ' Ann. Sc. Nat.,' 2nd ser., 1840, vol. xiv, p. 14, fig. 6, pi. i 

 {Drosera). St. Hilaire, ' Comptes Rendus,' ix, p. 437. 

 3 Hance, 'Hook. Joum. Botany,' 1849, vol. i, p. 141, pi. v. 



* Booth, ' Gard. Chron.,' Jan. Ist, 1853, p. 4. 



Lindley, ' Theory of Horticulture,' ed. 2, p. 273. 



* ' Hook. Joum. of Botany,' 1852, iv, p. 206. See also the curious 

 Begonia genvmipara, ' Hook. fil. Illust. Himal. Plant.,' t. xiv. 



