66 ON LEAVES. 



You may reccollect my observing, that a number of years 

 frequently elapsed before the buds formed on the stem or 

 branches of a tree attained sufficient strength to force their 

 way through the successive layers of new bark which an- 

 nually enclosed them; while others vigorously pushed 

 through this barrier the first year. Buds usually begin to 

 be formed in the month of August, and remain in a la- 

 tent state during the winter, when they are commonly 

 called eyes: the following spring they shoot; but they 

 cannot properly be called buds till the scales are formed 

 by the degeneration of the external leaves of the shoot. 



It is heat which determines the period of budding of a 

 plant. A branch turned towards the south, or introduced 

 into a greenhouse, will shoot long before the rest of the 

 tree ; the budding begins to appear first near the extrem- 

 ity of the branches where the wood is most soft and ten- 

 der. 



Emily. I should have imagined that the base of the 

 branch which the sap first reaches would have budded 

 earliest. 



Mrs. B. In the larch, and many other trees whose 

 branches are equally hard throughout, this is the case ; 

 but the superior facility of piercing through the tender 

 part of a branch more than compensates for the earlier 

 supply of food. 



The scales of buds are often coated with a sort of glu- 

 tinous varnish, which resists moisture ; some are lined with 

 a species of down or fur, to preserve the internal shoot 

 from cold. 



Caroline. But can down or fur result from the degen- 

 eration of leaves ? Such a beneficent provision for the 

 protection of the shoot would seem to indicate, that the 

 bud of a distinct organ is specifically designed for that 

 purpose. 



Mrs. B. Such is no doubt equally its destination, 

 whether it originate in the abortion of another organ, or 

 whether expressly created for that purpose : nor is it difn- 



351. What has before been said of bulbs remaining in a latent state! 

 352. When do buds usually begin to form; how long do they remain in 

 embryo state; what are they then called; and when do they shoot forth'? 

 353. What determines the period of the budding of a plant! 354. 

 What proves this 1 ? 355 In what part of the branch near the base 

 or the extremity does budding first take place! 856. 'With what are 

 scales of buds sometimes coated and with what are some lined! 



