128 MOKPHOLOGY, OK COMPARATIVE ANATOMY. 



ovules, is called the ovary (figs. 244 & 245, a, a') ; the upper part 

 of the carpel is frequently attenuated into a slender column called 

 the style (c), at the extremity of which is a terminal glandular orifice 

 or stigma (b, 6), the borders of which are often more or less thick- 

 ened or developed into processes of various kinds. Sometimes the 

 stylar prolongation does not exist ; and then the stigma is sessile 

 upon the ovary. 



The pistils are undoubtedly formed of carpels (carpellary leaves) in 

 most instances. In some cases they appear to be formed by an expansion 

 of the receptacle or axis of the flower, as in Typha and Naias ; while 

 their structure and venation are in some cases neither those of a leaf nor 

 of an axis, but, as it were, intermediate between the two. 



Phyllody- The foundations of the doctrine that the carpels are 

 metamorphosed leaves rest upon a very wide basis. The following 

 observations include examples of some of the most important classes 

 of proofs : 1 . The carpel ordinarily possesses more of the character 

 of a true leaf, as regards texture and colour, than the stamens or petals 

 approaching to the sepals, which we have seen to pass insensibly 

 through the bracts into ordinary leaves. The resemblance is sometimes 

 heightened during the development of the fruit, as we see in the legumes 

 of some species of Cassia, and still more in the bladder-like pod of 

 Coluteu. 2. Abundant examples exist of the substitution of petals for 

 stamens and pistils in abnormal flowers ; and an almost equally common 

 monstrosity consists in the substitution of isolated stunted green leaves for 

 the carpels. In the Double Cherry, cultivated in shrubberies for the sake 

 of its blossom, the stamens are generally replaced by petals, while the 

 centre of the flower is mostly occupied by a pair of green leaves. (The 

 single, fertile Cherry frequently has two pistils developed instead of 

 one.) In a common monstrosity of the White Clover, the pod is usually 

 replaced by a more or less perfect green leaf 5 the same occurs in garden 

 Roses, where tufts of green leaves replace the pistils ; and, in fact, 

 examples of this kind are very abundant. 3. The more or less stunted 

 green leaves which represent the carpels in the above-mentioned monsters 

 frequently exhibit on their margins structures varying in character from 

 almost perfect rudiments of ovules to cellular papillae and leafy lobules. 

 This is observed in the monstrous Clover, and has been especially remarked 

 also in monstrous flowers of cultivated (forced) Tulips, of various Cruci- 

 ferae, Ranunculacese, Scrophulariaceae, &c. The abnormal conditions in 

 these cases are analogous to the normal condition in Coniferse and Cyca- 

 deae, the Gymnosperms, where the ovules are always naked on open 

 carpels. 4. The production of ovules on the margins of carpels is analo- 

 gous to what is seen in the development of adventitious buds on vegetative 

 leaves, as in Bryophyttum, &c. Such buds, however, occur sometimes on 

 the upper surface of leaves ; and we find some carpels, as in Nyrnphcea, 

 Butomus, &c., with ovules developed more or less extensively over the in- 

 ternal face. 5. The disposition or arrangement of the vascular bundles 

 is usually that of the leaf, not that of the branch. 6. The structure, de- 

 velopment, and mode of growth generally are those of the leaf and not 

 of the branch. Exceptions, however, occur to the last two statements. 



