THE EVOLUTION OF THE FLOWER 127 



flower will well repay anyone who is interested 

 in the matter to study a little closely. If the 

 inner petals of a well-developed bloom of the 

 double Cherry are torn away, it will be found 

 that a small leaf occupies the place of the usual 

 carpel. This leaf has the two edges folded 

 towards each other, and the midrib is greatly 

 prolonged, having a little knob at the summit. 

 Now if this process be compared with the normal 

 carpel of a single Cherry blossom, it is quite easy 

 to see that the two sides of the leaf represent the 

 walls of the ovary, whilst the elongated process 

 can be none other than the style. 



When the carpels have passed their maturity 

 it is not at all an uncommon thing for them to 

 develop into very leaf-like organs. This is the 

 case in the seed vessels of the Pea, where it is 

 discernible that the two sides of the pod are not 

 unlike the lobes of a leaf joined together by a 

 midrib. A most suggestive monstrosity is occa- 

 sionally seen in the case of the Pea pod. This 

 happens when for some reason the ovules fail to 

 develop and the two sides of the pod do not 

 close together in the normal fashion. When this 

 is the case it is seen that the lobes of the seed 

 vessel are still more leaf-like than is usually the 

 case. Small projections are to be observed along 



