Rev. P. Keith on the Structure of Living Fabrics: 127 



now agreed to regard it as an involucrum. The Scale is a 

 thin, chaffy, and membranaceous substance, forming part of the 

 fructification of a variety of plants that produce incomplete 

 flowers, and constituting their calyx. It may be seen in the 

 catkins of the Willow and in the cones of the Fir. In the 

 former it is a proper calyx, in the latter it is a common calyx. 

 The Corolla is the interior envelope of the flower, investing 

 the central parts, but invested b}' the calyx. It is generally 

 of a finer and more delicate texture than the calyx, and is of 

 all the parts of the fructification the most showy and orna- 

 mental, being always, or with but few exceptions, that which 

 is the most highly coloured, as well as that from which the 

 flower imparts its rich and fragrant perfume, — its croceos odores, 

 — delighting at the same time both the sight and smell. To 

 this most elegant part of the fructification, the term Corolla 

 has been very happily applied by Linnaeus, signifying as it 

 does in the original, a crown or chaplet of flowers. 



Et modo solvebam nostra de fronte corollas. — Propert. i. 5. 21. 



Like the calyx, the corolla consists either of a single piece 

 called a petal, or of several distinct pieces called petals. In 

 the former case it is said to be monopetalous; in the latter 

 case it is said to be dipetalous, tripetalous, or tetrapetalous, 

 according to the number of distinct petals. The monopeta- 

 lous corolla is regarded as divisible into three parts, — the tube, 

 the mouth, the border. The tube is the lower portion, cylin- 

 drical and inflated. The mouth is the middle portion, often 

 beset with fine hairs, or with small projecting scales, so as 

 nearly to shut it up. The border is the upper and expanding 

 extremity. In its general contour it is bell-shaped, or club- 

 shaped, or funnel-shaped, or wheel-shaped. In the polype- 

 talous corolla, each petal is regarded as divisible into a claw 

 and border, the aggregate contour assuming many forms, 

 amongst which the most remarkable are the cruciform and the 

 papilionaceous. Like the calyx the corolla is not to be re- 

 garded as absolutely essential to the botanical notion of a 

 flower, because, in some flowers, it is wanting. Yet, where 

 one only of the two envelopes is present, it is sometimes a mat- 

 ter of considerable difficulty to say which of them it is. Is it 

 a calyx, or is it a corolla ? Botanists have laid down several 

 rules on this subject, but no one that is quite satisfactory. In 

 cases of doubt we must be guided by analogy. 



The stamens, — an appellation borrowed from the Latin term 

 stavwn y a thread,— 



Et gracili geminas intenclunt stamine telas, — {Ovid. Mel. vi. ."54.) 



are substances of a very slender fabric, and of a thread-shaped 



