426 HYPERTROPHY OP THE 



first given off I am unable to say, as it was fully 

 developed when the fruit was brought to me." 



Enlargement of the leaves. Increase in the size or sub- 

 stance of leaves takes places in several ways, and affects 

 the whole or only certain portions of them. The sim- 

 plest form of this malformation is met with in our 

 cabbages, which, by the art of the gardener, have been 

 made to produce leaves of greater size and thickness 

 than those which are developed in the wild form. In 

 such instances the whole substance of the leaf is in- 

 creased in bulk, and the increase affects the fibrous 

 framework of the leaves as well as the cellular portions, 

 though the exaggerated developnient of the latter is 

 out of proportion to that of the former. 



In some species of Podocatyus there may occasionally 

 be seen at the base of the branchlets a dozen or more 

 fleshy scales, of a rose colour, passing gradually into 

 the ordinary leaves of the plant, and evidently analogous 

 to the three fleshy confluent bracts which surround the 

 ripe fruit. 



In other instances, while the fibrous framework of 

 the leaf retains its usual degree of development, the 

 cellular parenchyma is developed in excess, and, if the 

 increase is so arranged that the number of superposed 

 layers of the cellular tissue is not increased, or their 

 thickness exaggerated, then we get such leaves as those 

 of the " kail," or of the " Savoys " leaves, which are 

 technically called by descriptive botanists " folia bul- 

 lata." In such leaves the disc of the leaf, rather than 

 the margin, is increased and its surface is thrown up 

 into little conical projections, which are hollow on the 

 under side. 



But leaves may increase beyond their usual size with- 

 out such grave alterations of form as those to which 

 allusion has just been made. It is well known that 

 if a tree be cut down and new shoots be sent out from 

 the stump, the leaves formed on these shoots very 

 often greatly oxrppfl the ordinary ones in dimonsions. 



