1899.] NATURAL SCIENCES OF PHILADELPHIA. 115 



all annual, but they become very wiry after death, and continue 

 apparently for all time to aid in sustaining the plant's attachment 

 to its support until violently separated by external forces. 



XIV. Morphology of the Grape. 



In referring to the grape or other vitaceous plants, it is custom- 

 ary to say of the tendril that it is a reduced 

 branch. It was long a puzzle to me that a 

 branch should appear on the opposite side of a 

 leaf, which leaf should have no axillary bud, 

 and, further, it seemed remarkable that when 

 there was an axillary bud at the base of the 

 leaf, there was no tendril on the opposite 

 side. 



I have since learned that in these cases the plant simply presents 

 to us phenomena very common in plants, especially when forming 

 an inflorescence, of displacing the leading stem, 

 and replacing the leader by the growth of the 

 axillary bud. What was the leader is pushed 

 on one side, and seems to be, what Avriters on 

 the vine assume the tendril to be, a mere 

 branch. In vigorous branches of the grape 

 vine, there seems occasionally to be an 

 axillary bud opposite the tendril, but this is 

 simply a supra- axillary bud, the upper of the two having advanced 

 to the position of a leading stem, when the former leader had been 

 reduced to the condition of a tendril. 



The fact is of importance in tracing the genital relationship of 

 the order of grape vines with other families. There is much in 

 Vitaceffi to suggest an alliance with rhamnaceous plants. In 

 Celastracese, for instance, the character noted in the grape of 

 having the tendril opposite a leaf without an axillary bud is want- 

 ing simply owing to the opposite -leaved method of carrying it& 

 foliage. How the growth-energy has been diverted from the 

 leading shoot to the axillary buds is shown in the inflorescence of 

 Euonymus Japonicus. With a further suppression of the leader 

 there would have been dichotomous branching. With an alternatfr 

 system of leafage, the central axis would have been pushed aside 



Fig. 5. 



