Grape Tendrils. 



61 



tion is exactly that of tendrils. Some of their basal 

 branches are tendrils, and others partake of the nature 

 of both tendril and flower stem. Evidently the tendrils 

 and flower clusters of grapes are homologous with the 



Fig. 48. A. Apex of a growing grape-vine, a. The 

 main stem developed as a tendril, b b. Bracts in the 

 axils of which grow branches of the tendril. Above is 

 another tendril surpassing the branch which seems to 

 be the main stem, c. Reserve or winter bud. d. A bud 

 which becomes a short stem bearing a few leaves. B. A 

 grape tendril which was called upon to support a heavy 

 vine. C. The pinnate leaf of a sweet-pea, showing all 

 but one pair of leaflets developed as tendrils. 



primary stems. Probably the ancestors of grapes had no 



tendrils but in climbing used the flower clusters as holdfasts. 



Observe the buds. Since all the normal axillary buds 



develop immediately, we would expect to find in your speci- 



