BRACTS. ANALOGY OP SEPALS AND LEAVES. '297 



some exotic species, cultivated in our drawing-rooms, it is white, 

 arid is commonly regarded as the flower. These bracts may be 

 regarded, as establishing the transition of form and structure, 

 between the common leaves of the plant, and those modified 

 or metamorphosed leaves, which form the perianth. Sometimes 

 they can scarcely be distinguished from the former; whilst 

 in other cases, they are brightly coloured, and more closely 

 resemble the latter ; and, in the Hydrangea and some other plants, 

 they really constitute the most showy portion of the flower; being 

 very large and brilliant, whilst the flower they enclose is so small, 

 as to be almost overlooked. In many instances, the bracts form 

 so gradual a transition, between the true leaves and the parts of 

 the flower, that it is very difficult to say where the former end 

 and the latter begins. This is the case in the double Paeony, 

 a plant now very common in gardens. Its lower leaves are very 

 complex in their structure, being divided into a great number of 

 segments (. 235) ; in tracing them up the stem, they are found 

 to become simpler and simpler in their character as they approach 

 the flower, and also to diminish in size ; and at the same time, 

 their spiral arrangement round the stem becomes more evident, 

 the intervals between them being diminished. In this manner, 

 they may be at last traced into the outermost whorl of the leafy 

 parts composing the flower ; and it is quite impossible to specify 

 the exact place, at which the true leaves may be said to end, or 

 the calyx to commence. 



458. From this it would appear, that there is no essential 

 difference between the sepals of the calyx and regular leaves ; 

 and examination of their structure bears out the conclusion. If 

 we take an example from a plant, in which the sepals are distinct 

 from each other, and green, we should find it difficult to assign 

 any important characters, in which they differ from leaves. They 

 possess two layers of cuticle, furnished with stomata; having 

 green cellular tissue or parenchyma between them, supported by 

 veins consisting of woody fibre and vessels. There are many 

 cases, however, in which the calyx is brightly coloured, equalling 

 the corolla in beauty, and even surpassing it in brilliancy. In 

 the Lilies and Tulips, we find the perianth composed of six 



