ON THE NATURE OF STIPULES 203 



base of the leaf. Frequently, however, leaves occur 

 with only one stipule, while at the other side of the 

 leaf is a tooth-like projection, into which a weak nerve 

 enters, which is wanting on the other side of the leaf, 

 or rather is replaced by the nerve of the stipule. In 

 some cases there is no tooth, but the side of the leaf 

 which has no stipule is broader than the other. Some- 

 times, again, there are no stipules, but the leaf has a 

 tooth on each side, which may cut into the leaf almost 

 to the base. 



Stenzel therefore regards the so-called stipules of 

 II. guttatum as being really leaflets. In that case, how- 

 ever, all the stipules of Helianthemum must be so re- 

 garded, and the case appears to be one which requires 

 further study. The same argument might be advanced 

 in the case of many undoubted stipules; e.g. Pansy. 



There has also been a good deal of difference of 

 opinion in the case of the Elders (Sambucus). In 8. 

 canadensis , Tyler (21) says that stipules are typically 

 developed. 



Bentham and Hooker (' Gen. Plant.' ii. 3) say, 'Petiolo 

 basi nudo glanduloso v. foliolis stipulseformibus aucto.' 



In our Common Elder (S. nigra) the leaves are 

 sometimes exstipulate, sometimes (fig. 31, p. 26) have 

 minute stipules ; on the other hand, the Dwarf Elder 

 (S. Elndus) has small leaflets at the base of the leaf- 

 stalk, which, in Bentham's words, ' look like stipules.' 



In the Black Bryony (Tamus communis), there is at 



