LABORATORY STUDIES OF BUDS 25 



Exercise IX. The Number and Position of the Buds 



The position of buds in general, with reference to the leaves of the 

 previous season, must have already attracted attention. What is that 

 position? "When two or more buds occur together they have, rela- 

 tively to one another, one of two characteristic arrangements, as seen 

 in the following species. 



Red Maple. — Ilow many buds in a group? Which ones maybe 

 termed extra, or accessory ? 



Draw enough of the twig to show the essential relations of the buds, 

 both to the leaf scar and to one another. 



Pipevine. — Examine the neighborhood of the leaf scar with the 

 lens. Cut a longitudinal section of the stem through the middle of 

 the scar. Examine the cut surfaces of the bark. Growing points, 

 distinguished by superior greenness, can be made out. Note their 

 number and relative position. 



Make a drawing (enlarged) to show the disposition of accessory 

 buds here found. 



Exercise X. The Wintering of the Young Shoot 



Refer to the records and drawings made in the laboratory for the 

 materials of a comparative account of buds, with reference to their 

 adaptations to winter conditions. Protection against sudden chilling 

 is sometimes perfect; in other cases temperature seems to be disre- 

 garded. Arrange the various modes of meeting the dangers of cold 

 in an orderly manner in your acconnt. 



Are there any other sources of destruction besides low temperature? 

 If so, wdiat? And are buds protected against these dangers? 



Exercise XL The Development or Unfolding of Buds i 



The Lilac, forced to gi-ow indoors, may be studied. Determine 

 what parts have grown since the bud came out of the typical winter 

 state. Have all grown equally? Have some not grown? 



Draw enough to show what happens to the different members of 

 the winter bud. 



If possible, compare with the Lilac the unfolding buds of two other 

 species, as the Button wood and the Sycamore ]Maple. 



Exercise XII. The Nondevelopment of Buds 



Select a branch of the Horse-chestnut five years old. or thereabouts. 

 Count the total number of leaf scars. Of these, how many now^ sub- 

 tend buds, or have subtended buds? In how many cases have buds 

 developed into branches or flower clusters? 



1 This may be a home experiment. 



