q2 PISTIL. [CHAP. 



some of the leaf-organs, especially those of reproduc- 

 tion, under certain conditions, assuming the character 

 of other organs. Thus stamens, in many plants, have a 

 strong tendency to lose their character as staminal-leaves 

 and to assume that of petals, as you may find if you 

 compare a double with a single Rose. There is, indeed, a 

 Rose in which all the organs of the flower, excepting the 

 sepals, so far depart from their normal character as to 

 become small foliage-leaves, all coloured green, and firm in 

 texture. 



The chief difficulty in the way of accepting the notion of 

 the essential oneness and homology of all the leaf-organs of 

 a plant rests principally in the wide dissimilarity existing, in 

 the usual condition of things, between the leaves of the stem 

 and the stamens or carpels, especially the latter. But the 

 acceptance and thorough appreciation of this view you will 

 find furnishes an invaluable key to the comprehension of all 

 the various modifications which the pistil and its parts, the 

 carpels undergo ; and it is especially with reference to these 

 that we shall at present concern ourselves. 



Fig. G7. Pod [leginne] of Pea, partially laid open to show the attaciimenl 

 of the Seeds to the ventral suture. 



20. Take a pistil of the simplest possible structure, — the 

 pistil of the Pea, Dhak, or any of their allies, for example. 

 Vou have here an apocarpous pistil, consisting of a single 



