122 Moore : The study of winter buds 



or three. The number of leaves in the bud is six or four plus a 

 pair of papillae in position for the fourth or third whorl of leaves, 

 A study of the microscopic sections of the bud during the 

 winter and spring shows no organization of new leaves. At the 

 time of the swelling of the buds in early April, new growths 

 appear at the meristematic point (figure 33, s/.). Field studies 

 during the period of the unfolding of the leaves show with perfect 

 clearness that these new growths are the first pairs of scales of the 

 future terminal bud, the bud of the next season. The new scales; 

 admirably protected by the encircling bases of the petioles of 

 leaves, show exceedingly slow growth in comparison with the 

 normal leaves, and an unmistakable differentiation into bud cov- 



erings 



Hipp 



number of leaves exists in the bud at the beginning of winter. In 

 addition two pairs of tiny scales appear as papillae in the meriste- 

 matic point (figure 36, s.fX As they develop in the spring, the 

 long, pointed character, indicative of scales, becomes prominent. 

 The number of whorls of leaves in the bud of the main branches 

 is generally four, sometimes five. This corresponds with the 

 usual number of nodes developed In the branches during previous 

 seasons. It is an interesting observation that the number of nodes 

 is always less where the terminal bud is a flower bud. 



Fagus ainciicana and Fagiis sylvatica have their leaves well 

 developed in the bud and contain the full number for the season, 

 five to seven on the primary shoots, three to four on the secondary 

 ones. These leaves are, on the whole, farther advanced in regard 

 to form and structure than those found on any other buds 

 examined. 



The number of leaves in the buds of Fraxinns mnericana, 

 Liriodendron Tulip if era, and Hicoria ovata is more or less readily 

 determined with the aid of the dissecting microscope, and agrees 

 in each case with the usual number of nodes on the twigs of pre- 



three or four whorls in Fraxiuus, seven to nine 

 leaves In Liriodendron, and five to seven leaves in Hicoria. A 

 comparative study of the microscopic sections of buds during the 

 winter months and the observations in the field durins" the unfold- 



vious seasons 



tj 



ing of the buds gives undoubted evidence that here, too, the full 



