BUD-SCALES 



111 



232. The scales of buds are special kinds of bracts. In 

 some cases each scale represents an entire leaf; in others, 

 it represents a petiole or stipule. 

 In the expanding pear, maple, lilac, 

 hickory and horse-chestnut buds, 

 note the gradation from dry scales to 

 green leaf-like bodies. When the 

 winter scales fall by the pushing out 

 of the young shoot, scars are left: 

 these scars form "rings," which mark 

 the annual growths. (See Chap. VII.) 

 The scales of bulbs are also special 

 kinds of leaves or bracts. In some 

 cases they are merely protective bodies', 

 in others they are storehouses. We 

 have found (45) that the presence of 

 scales or bracts is one means of dis- 

 tinguishing underground stems from 

 roots. 



173. Red clover. Leaves 

 3-foliolate. 



REVIEW. What are considered to be the fundamental or type 

 forms from which the parts of plants are derived? How do the forms 

 of plants interest us? What is morphology? What is meant by trans- 

 formation and modification as used by the morphologist? What is 

 meant by homologous parts? Analogous parts? Tell how one may 

 determine the morphology of any part. What is a cladophyllum? 

 Phyllodium? Show a specimen of one or the other, or both (canned 

 asparagus can always be had in the market). What is the morphology 

 of most thorns? Explain the thorns of hawthorn. What are bristles, 

 prickles and hairs? Why do spines and bristles exist? Explain what 

 a bract is. A bud-scale. A bulb-scale. 



