FRUIT- VARIATION 99 



differences in the physiology of the plant. For in- 

 stance, Carriere, 1 after having noticed the formal 

 variations of the leaves of the ivy according to its 

 mode of life (climbing, or entirely independent and 

 tree-like), adds the significant fact that the leaves of 

 the climbing plant when inserted in the soil readily 

 start an independent life, and emit roots very soon, 

 while those of the independent form do so only with 

 great difficulty. Here is certainly an inportant 

 physiological difference ; not perhaps in itself, but as 

 indicating differences in the structure and life of the 

 whole plant. 



Fruits vary as well as leaves ; the same branch of a 

 peach-tree, for instance, bears peaches and nectarines ; 

 the same branch of an orange-tree bears oranges and 

 lemons ; the same branch of an apple-tree bears quite 

 different varieties of apples. Prof. Decaisne, who was 

 an authority in the matter of fruit trees, especially 

 apple and pear, observed 2 considerable variations 

 among the descendants of seeds of the same sort ; in the 

 course of a few years, from the same seeds, he obtained 

 six different forms of pear-tree, in which the fruits 

 were unlike, while differences also existed in the 

 general morphology of the plant. 



1 Polymorphisme des Vegetaux. Revue Horticole, 1886, p. 209. 



2 De la Variabilite de F Espece dans le Poirier. C. R. Acad. des 

 Sciences, 1863. 



