1 6 Traces of Unity in Plants. 



by no means constant, and in many instances the latter 

 organs are coloured in certain parts of the surface, or at 

 the edges or tips, while at the same time the texture is 

 more delicate and petaloid than usual. Within the 

 calyx of the common pink, for example, there is often a 

 second calyx tinted and changed in this manner. Some- 

 times it is difficult to say whether the floral envelope be 

 a calyx or corolla. Sometimes the common leaves of 

 the stem are coloured in a greater or less degree imme- 

 diately before the period of flowering, or the leaves in 

 the neighbourhood of the flowers may be constantly 

 decorated in this manner. On the stem of the tulip 

 there is often an anomalous organ intermediate between 

 the leaf and the petal which is green in the part con- 

 tiguous to the stem and brightly coloured in the 

 remaining portion. Indeed, it is certain that petals and 

 sepals and leaves would not run together as they do if 

 they were not connatural in the fullest sense of the 

 word. 



The vague and ill-defined organs known as nectaries 

 afford a natural passage from the corolla to the stamens : 

 or an analogous mode of transition may be found in the 

 changes which have come to pass in various double 

 flowers. In many roses, for example, in the midst of 

 petals perfectly developed and coloured, are other petals 

 formed in such a manner as to resemble the filaments 

 and anthers of the stamens. In many double poppies, 

 also, perfect anthers are met with on some of the petals 

 and antheroid tumours on others : while at the same 

 time the discoid surfaces of these organs show a dispo- 

 sition to shrink into the form of filaments. 



Nor are the anthers distinguished in any absolute 

 manner by the presence of the pollen. The pollen in its 

 most perfect condition consists of minute grains con- 



