STEM A.PPENDAGES. 



107 



petiole is attached, are called sinuses, and the shape and 

 depth of these afford distinguishing characters. These 

 are the principal terms used in describing the shape of 

 grape leaves, and the strikingly different forms can be 

 described so that they may be recognized ; but it is often 

 the case that the difference in foliage in distinct varie- 



FIG. 33. THE YEDDO. 



ties is so slight that, although it is readily perceived by 

 a practiced eye, it is not possible to express these dis- 

 tinctions in words. 



There are also many other marks that aid us in dis- 

 tinguishing the different varieties perhaps the most 



