ON STIPULES 21 



en sont privees.' This suggestion started me on 

 the present inquiry. No one, so far as I know, 

 had attempted to answer Vaucher's question, which 

 is one of considerable interest, and might be asked 

 with reference to several other groups besides the 

 genus Helianthemum. The results of my observations 

 have been embodied in several Memoirs which the 

 Linnean Society has done me the honour to publish in 

 their ' Journal,' and I now propose to bring together 

 those portions which seem to be of general interest. 



Fig. 23. Shoot of Helianthemum celandicum. Slightly enlarged. 



Fig. 22 represents a shoot of Helianthemum vulgar e 

 (the Common Rock Rose), with stipules ; Fig. 23, one of 

 HeliantJiemum oelandicum, which has none. 



Malpighi, in his ' Anatomy of Plants ' (1671), seems 

 to have been the first who mentions these organs, which 

 he terms (p. 29) 'folia caduca,' in opposition to the ordi- 

 nary and generally, though by no means always, more 

 permanent leaf-blades. Almost at the same time (1672) 

 they were noticed and described by our countryman 

 Grew, who called them interfoils. 1 Linnasus gave them 

 1 The Anatomy of Plants, p. 146. 



